15620504981 has 2 divisors, whose sum is σ = 15620504982. Its totient is φ = 15620504980.

The previous prime is 15620504917. The next prime is 15620505011. The reversal of 15620504981 is 18940502651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11234092081 + 4386412900 = 105991^2 + 66230^2 .

It is a cyclic number.

It is not a de Polignac number, because 15620504981 - 2⁶ = 15620504917 is a prime.

It is a super-2 number, since 2×15620504981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15620509981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7810252490 + 7810252491.

It is an arithmetic number, because the mean of its divisors is an integer number (7810252491).

Almost surely, 2^15620504981 is an apocalyptic number.

It is an amenable number.

15620504981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15620504981 is an equidigital number, since it uses as much as digits as its factorization.

15620504981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 41.

The spelling of 15620504981 in words is "fifteen billion, six hundred twenty million, five hundred four thousand, nine hundred eighty-one".