2145378690 has 128 divisors (see below), whose sum is σ = 7041323520. Its totient is φ = 452646144.

The previous prime is 2145378667. The next prime is 2145378691. The reversal of 2145378690 is 968735412.

2145378690 is a `hidden beast` number, since 21 + 4 + 537 + 8 + 6 + 90 = 666.

2145378690 is digitally balanced in base 10, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×2145378690² = 9205299447012232200, which contains 22 as substring.

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

2145378690 is strictly pandigital in base 10.

It is not an unprimeable number, because it can be changed into a prime (2145378691) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19089 + ... + 68228.

It is an arithmetic number, because the mean of its divisors is an integer number (55010340).

It is a 1-persistent number, because it is pandigital, but 2⋅2145378690 = 4290757380 is not.

Almost surely, 2^2145378690 is an apocalyptic number.

2145378690 is an abundant number, since it is smaller than the sum of its proper divisors (4895944830).

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

2145378690 is a wasteful number, since it uses less digits than its factorization.

2145378690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87353 (or 87347 counting only the distinct ones).

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

The square root of 2145378690 is about 46318.2328030766. The cubic root of 2145378690 is about 1289.7374803820.

The spelling of 2145378690 in words is "two billion, one hundred forty-five million, three hundred seventy-eight thousand, six hundred ninety".