15487614721 has 4 divisors (see below), whose sum is σ = 15488941572. Its totient is φ = 15486287872.

The previous prime is 15487614689. The next prime is 15487614733. The reversal of 15487614721 is 12741678451.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12240324496 + 3247290225 = 110636^2 + 56985^2 .

It is a cyclic number.

It is not a de Polignac number, because 15487614721 - 2⁵ = 15487614689 is a prime.

It is a super-2 number, since 2×15487614721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15487644721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 645760 + ... + 669313.

It is an arithmetic number, because the mean of its divisors is an integer number (3872235393).

Almost surely, 2^15487614721 is an apocalyptic number.

It is an amenable number.

15487614721 is a deficient number, since it is larger than the sum of its proper divisors (1326851).

15487614721 is a wasteful number, since it uses less digits than its factorization.

15487614721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326850.

The product of its digits is 376320, while the sum is 46.

The spelling of 15487614721 in words is "fifteen billion, four hundred eighty-seven million, six hundred fourteen thousand, seven hundred twenty-one".