15620000021 has 2 divisors, whose sum is σ = 15620000022. Its totient is φ = 15620000020.

The previous prime is 15619999979. The next prime is 15620000087. The reversal of 15620000021 is 12000002651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15501495025 + 118504996 = 124505^2 + 10886^2 .

It is a cyclic number.

It is not a de Polignac number, because 15620000021 - 2¹⁸ = 15619737877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15620000321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7810000010 + 7810000011.

It is an arithmetic number, because the mean of its divisors is an integer number (7810000011).

Almost surely, 2^15620000021 is an apocalyptic number.

It is an amenable number.

15620000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

15620000021 is an equidigital number, since it uses as much as digits as its factorization.

15620000021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

Adding to 15620000021 its reverse (12000002651), we get a palindrome (27620002672).

The spelling of 15620000021 in words is "fifteen billion, six hundred twenty million, twenty-one", and thus it is an aban number.