15956297281 has 2 divisors, whose sum is σ = 15956297282. Its totient is φ = 15956297280.

The previous prime is 15956297267. The next prime is 15956297347. The reversal of 15956297281 is 18279265951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14306312881 + 1649984400 = 119609^2 + 40620^2 .

It is a cyclic number.

It is not a de Polignac number, because 15956297281 - 2¹⁹ = 15955772993 is a prime.

It is a super-2 number, since 2×15956297281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15956295281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7978148640 + 7978148641.

It is an arithmetic number, because the mean of its divisors is an integer number (7978148641).

Almost surely, 2^15956297281 is an apocalyptic number.

It is an amenable number.

15956297281 is a deficient number, since it is larger than the sum of its proper divisors (1).

15956297281 is an equidigital number, since it uses as much as digits as its factorization.

15956297281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2721600, while the sum is 55.

The spelling of 15956297281 in words is "fifteen billion, nine hundred fifty-six million, two hundred ninety-seven thousand, two hundred eighty-one".