15951640 has 64 divisors (see below), whose sum is σ = 38304000. Its totient is φ = 5961600.

The previous prime is 15951631. The next prime is 15951647. The reversal of 15951640 is 4615951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15951647) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 105565 + ... + 105715.

It is an arithmetic number, because the mean of its divisors is an integer number (598500).

Almost surely, 2^15951640 is an apocalyptic number.

15951640 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 15951640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19152000).

15951640 is an abundant number, since it is smaller than the sum of its proper divisors (22352360).

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

15951640 is a wasteful number, since it uses less digits than its factorization.

15951640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 15951640 is about 3993.9504253308. The cubic root of 15951640 is about 251.7300796789.

The spelling of 15951640 in words is "fifteen million, nine hundred fifty-one thousand, six hundred forty".