21170520472 has 8 divisors (see below), whose sum is σ = 39694725900. Its totient is φ = 10585260232.

The previous prime is 21170520467. The next prime is 21170520557. The reversal of 21170520472 is 27402507112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21170520472² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1323157522 + ... + 1323157537.

Almost surely, 2^21170520472 is an apocalyptic number.

It is an amenable number.

21170520472 is a deficient number, since it is larger than the sum of its proper divisors (18524205428).

21170520472 is a wasteful number, since it uses less digits than its factorization.

21170520472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646315065 (or 2646315061 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 31.

The spelling of 21170520472 in words is "twenty-one billion, one hundred seventy million, five hundred twenty thousand, four hundred seventy-two".