7936553861721 has 45 divisors (see below), whose sum is σ = 12594949747501. Its totient is φ = 4979528051328.

The previous prime is 7936553861647. The next prime is 7936553861837. The reversal of 7936553861721 is 1271683556397.

The square root of 7936553861721 is 2817189.

It is a perfect power (a square), and thus also a powerful number.

7936553861721 is a `hidden beast` number, since 7 + 9 + 3 + 6 + 5 + 5 + 3 + 8 + 617 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18295538121 + 7918258323600 = 135261^2 + 2813940^2 .

It is not a de Polignac number, because 7936553861721 - 2¹¹ = 7936553859673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7936553861021) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 431020711 + ... + 431039123.

Almost surely, 2^{7936553861721} is an apocalyptic number.

7936553861721 is the 2817189-th square number.

7936553861721 is the 1408595-th centered octagonal number.

It is an amenable number.

7936553861721 is a deficient number, since it is larger than the sum of its proper divisors (4658395885780).

7936553861721 is an frugal number, since it uses more digits than its factorization.

7936553861721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36872 (or 18433 counting only the distinct ones).

The product of its digits is 57153600, while the sum is 63.

The spelling of 7936553861721 in words is "seven trillion, nine hundred thirty-six billion, five hundred fifty-three million, eight hundred sixty-one thousand, seven hundred twenty-one".