15606640081 has 2 divisors, whose sum is σ = 15606640082. Its totient is φ = 15606640080.

The previous prime is 15606640003. The next prime is 15606640103. The reversal of 15606640081 is 18004660651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13298702400 + 2307937681 = 115320^2 + 48041^2 .

It is a cyclic number.

It is not a de Polignac number, because 15606640081 - 2¹³ = 15606631889 is a prime.

It is a super-2 number, since 2×15606640081² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 15606640081.

It is not a weakly prime, because it can be changed into another prime (15606640381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7803320040 + 7803320041.

It is an arithmetic number, because the mean of its divisors is an integer number (7803320041).

Almost surely, 2^15606640081 is an apocalyptic number.

It is an amenable number.

15606640081 is a deficient number, since it is larger than the sum of its proper divisors (1).

15606640081 is an equidigital number, since it uses as much as digits as its factorization.

15606640081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 37.

The spelling of 15606640081 in words is "fifteen billion, six hundred six million, six hundred forty thousand, eighty-one".