15661263427 has 2 divisors, whose sum is σ = 15661263428. Its totient is φ = 15661263426.

The previous prime is 15661263407. The next prime is 15661263469. The reversal of 15661263427 is 72436216651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15661263427 - 2¹¹ = 15661261379 is a prime.

It is not a weakly prime, because it can be changed into another prime (15661263407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7830631713 + 7830631714.

It is an arithmetic number, because the mean of its divisors is an integer number (7830631714).

Almost surely, 2^15661263427 is an apocalyptic number.

15661263427 is a deficient number, since it is larger than the sum of its proper divisors (1).

15661263427 is an equidigital number, since it uses as much as digits as its factorization.

15661263427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 43.

The spelling of 15661263427 in words is "fifteen billion, six hundred sixty-one million, two hundred sixty-three thousand, four hundred twenty-seven".