15249806981 has 2 divisors, whose sum is σ = 15249806982. Its totient is φ = 15249806980.

The previous prime is 15249806963. The next prime is 15249806993. The reversal of 15249806981 is 18960894251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14473293025 + 776513956 = 120305^2 + 27866^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15249806981 is a prime.

It is a super-2 number, since 2×15249806981² (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 (15249806921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7624903490 + 7624903491.

It is an arithmetic number, because the mean of its divisors is an integer number (7624903491).

Almost surely, 2^15249806981 is an apocalyptic number.

It is an amenable number.

15249806981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15249806981 is an equidigital number, since it uses as much as digits as its factorization.

15249806981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1244160, while the sum is 53.

The spelling of 15249806981 in words is "fifteen billion, two hundred forty-nine million, eight hundred six thousand, nine hundred eighty-one".