16521471956 has 12 divisors (see below), whose sum is σ = 31540992000. Its totient is φ = 7509759960.

The previous prime is 16521471949. The next prime is 16521471959. The reversal of 16521471956 is 65917412561.

It is a self number, because there is not a number n which added to its sum of digits gives 16521471956.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16521471959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187743956 + ... + 187744043.

It is an arithmetic number, because the mean of its divisors is an integer number (2628416000).

Almost surely, 2^16521471956 is an apocalyptic number.

It is an amenable number.

16521471956 is a deficient number, since it is larger than the sum of its proper divisors (15019520044).

16521471956 is a wasteful number, since it uses less digits than its factorization.

16521471956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375488014 (or 375488012 counting only the distinct ones).

The product of its digits is 453600, while the sum is 47.

The spelling of 16521471956 in words is "sixteen billion, five hundred twenty-one million, four hundred seventy-one thousand, nine hundred fifty-six".