15115593478981 has 2 divisors, whose sum is σ = 15115593478982. Its totient is φ = 15115593478980.

The previous prime is 15115593478963. The next prime is 15115593479009. The reversal of 15115593478981 is 18987439551151.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14918249632225 + 197343846756 = 3862415^2 + 444234^2 .

It is a cyclic number.

It is not a de Polignac number, because 15115593478981 - 2²³ = 15115585090373 is a prime.

It is a super-2 number, since 2×15115593478981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15115593478901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7557796739490 + 7557796739491.

It is an arithmetic number, because the mean of its divisors is an integer number (7557796739491).

Almost surely, 2^{15115593478981} is an apocalyptic number.

It is an amenable number.

15115593478981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15115593478981 is an equidigital number, since it uses as much as digits as its factorization.

15115593478981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432000, while the sum is 67.

The spelling of 15115593478981 in words is "fifteen trillion, one hundred fifteen billion, five hundred ninety-three million, four hundred seventy-eight thousand, nine hundred eighty-one".