2145387690 has 48 divisors (see below), whose sum is σ = 5669465256. Its totient is φ = 562723200.

The previous prime is 2145387667. The next prime is 2145387697. The reversal of 2145387690 is 967835412.

2145387690 is a `hidden beast` number, since 21 + 4 + 538 + 7 + 6 + 90 = 666.

2145387690 is digitally balanced in base 10, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 787981041 + 1357406649 = 28071^2 + 36843^2 .

It is a super-2 number, since 2×2145387690² = 9205376680807072200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

2145387690 is strictly pandigital in base 10.

It is not an unprimeable number, because it can be changed into a prime (2145387697) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 189901 + ... + 200880.

It is a 1-persistent number, because it is pandigital, but 2⋅2145387690 = 4290775380 is not.

Almost surely, 2^2145387690 is an apocalyptic number.

2145387690 is an abundant number, since it is smaller than the sum of its proper divisors (3524077566).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2145387690 is a wasteful number, since it uses less digits than its factorization.

2145387690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390855 (or 390852 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 2145387690 is about 46318.3299569404. The cubic root of 2145387690 is about 1289.7392838897.

The spelling of 2145387690 in words is "two billion, one hundred forty-five million, three hundred eighty-seven thousand, six hundred ninety".