15640623640 has 48 divisors (see below), whose sum is σ = 35518301280. Its totient is φ = 6198664320.

The previous prime is 15640623631. The next prime is 15640623641. The reversal of 15640623640 is 4632604651.

It is a self number, because there is not a number n which added to its sum of digits gives 15640623640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15640623641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 458785 + ... + 491695.

It is an arithmetic number, because the mean of its divisors is an integer number (739964610).

Almost surely, 2^15640623640 is an apocalyptic number.

15640623640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15640623640 is an abundant number, since it is smaller than the sum of its proper divisors (19877677640).

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

15640623640 is a wasteful number, since it uses less digits than its factorization.

15640623640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33140 (or 33027 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 37.

The spelling of 15640623640 in words is "fifteen billion, six hundred forty million, six hundred twenty-three thousand, six hundred forty".