1889540640 has 144 divisors (see below), whose sum is σ = 6944130648. Its totient is φ = 465113088.

The previous prime is 1889540591. The next prime is 1889540641. The reversal of 1889540640 is 460459881.

It can be written as a sum of positive squares in 4 ways, for example, as 759774096 + 1129766544 = 27564^2 + 33612^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

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

It is not an unprimeable number, because it can be changed into a prime (1889540641) 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, 31749 + ... + 69188.

Almost surely, 2^1889540640 is an apocalyptic number.

1889540640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1889540640 is an abundant number, since it is smaller than the sum of its proper divisors (5054590008).

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

1889540640 is a wasteful number, since it uses less digits than its factorization.

1889540640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100971 (or 100960 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 1889540640 is about 43468.8467755932. The cubic root of 1889540640 is about 1236.2854149684.

The spelling of 1889540640 in words is "one billion, eight hundred eighty-nine million, five hundred forty thousand, six hundred forty".