21673139524 has 9 divisors (see below), whose sum is σ = 37928509437. Its totient is φ = 10836422544.

The previous prime is 21673139489. The next prime is 21673139539. The reversal of 21673139524 is 42593137612.

The square root of 21673139524 is 147218.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 310393924 + 21362745600 = 17618^2 + 146160^2 .

It is a Duffinian 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 in 2 ways as a sum of consecutive naturals, for example, 257632 + ... + 331240.

Almost surely, 2^21673139524 is an apocalyptic number.

21673139524 is the 147218-th square number.

It is an amenable number.

21673139524 is a deficient number, since it is larger than the sum of its proper divisors (16255369913).

21673139524 is an frugal number, since it uses more digits than its factorization.

21673139524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147222 (or 73611 counting only the distinct ones).

The product of its digits is 272160, while the sum is 43.

The spelling of 21673139524 in words is "twenty-one billion, six hundred seventy-three million, one hundred thirty-nine thousand, five hundred twenty-four".