21162155639 has 8 divisors (see below), whose sum is σ = 21464727120. Its totient is φ = 20859926976.

The previous prime is 21162155633. The next prime is 21162155659. The reversal of 21162155639 is 93655126112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21162155639 - 2⁸ = 21162155383 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21162155596 and 21162155605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162155633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39944 + ... + 209570.

It is an arithmetic number, because the mean of its divisors is an integer number (2683090890).

Almost surely, 2^21162155639 is an apocalyptic number.

21162155639 is a deficient number, since it is larger than the sum of its proper divisors (302571481).

21162155639 is a wasteful number, since it uses less digits than its factorization.

21162155639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171409.

The product of its digits is 97200, while the sum is 41.

The spelling of 21162155639 in words is "twenty-one billion, one hundred sixty-two million, one hundred fifty-five thousand, six hundred thirty-nine".