15942640 has 100 divisors (see below), whose sum is σ = 43762824. Its totient is φ = 5400192.

The previous prime is 15942631. The next prime is 15942683. The reversal of 15942640 is 4624951.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 192039 + ... + 192121.

Almost surely, 2^15942640 is an apocalyptic number.

15942640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15942640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21881412).

15942640 is an abundant number, since it is smaller than the sum of its proper divisors (27820184).

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

15942640 is an frugal number, since it uses more digits than its factorization.

15942640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 15942640 is about 3992.8235623428. The cubic root of 15942640 is about 251.6827282899.

The spelling of 15942640 in words is "fifteen million, nine hundred forty-two thousand, six hundred forty".