21620654163013 has 4 divisors (see below), whose sum is σ = 21741439940640. Its totient is φ = 21499868385388.

The previous prime is 21620654163011. The next prime is 21620654163023. The reversal of 21620654163013 is 31036145602612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21620654163013 - 2¹ = 21620654163011 is a prime.

It is a super-2 number, since 2×21620654163013² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620654163011) 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, 60392888545 + ... + 60392888902.

It is an arithmetic number, because the mean of its divisors is an integer number (5435359985160).

Almost surely, 2^{21620654163013} is an apocalyptic number.

It is an amenable number.

21620654163013 is a deficient number, since it is larger than the sum of its proper divisors (120785777627).

21620654163013 is a wasteful number, since it uses less digits than its factorization.

21620654163013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120785777626.

The product of its (nonzero) digits is 155520, while the sum is 40.

Adding to 21620654163013 its reverse (31036145602612), we get a palindrome (52656799765625).

The spelling of 21620654163013 in words is "twenty-one trillion, six hundred twenty billion, six hundred fifty-four million, one hundred sixty-three thousand, thirteen".