21485641972 has 6 divisors (see below), whose sum is σ = 37599873458. Its totient is φ = 10742820984.

The previous prime is 21485641967. The next prime is 21485641987. The reversal of 21485641972 is 27914658412.

It can be written as a sum of positive squares in only one way, i.e., 18693999076 + 2791642896 = 136726^2 + 52836^2 .

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 as a sum of consecutive naturals, namely, 2685705243 + ... + 2685705250.

Almost surely, 2^21485641972 is an apocalyptic number.

It is an amenable number.

21485641972 is a deficient number, since it is larger than the sum of its proper divisors (16114231486).

21485641972 is a wasteful number, since it uses less digits than its factorization.

21485641972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5371410497 (or 5371410495 counting only the distinct ones).

The product of its digits is 967680, while the sum is 49.

The spelling of 21485641972 in words is "twenty-one billion, four hundred eighty-five million, six hundred forty-one thousand, nine hundred seventy-two".