1553291108721 has 45 divisors (see below), whose sum is σ = 2550668258523. Its totient is φ = 941313772080.

The previous prime is 1553291108711. The next prime is 1553291108741. The reversal of 1553291108721 is 1278011923551.

The square root of 1553291108721 is 1246311.

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

1553291108721 is a `hidden beast` number, since 1 + 5 + 532 + 9 + 1 + 10 + 87 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 127798385121 + 1425492723600 = 357489^2 + 1193940^2 .

It is not a de Polignac number, because 1553291108721 - 2¹¹ = 1553291106673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1553291108711) 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, 123378495 + ... + 123391083.

Almost surely, 2^{1553291108721} is an apocalyptic number.

1553291108721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1553291108721 is the 1246311-st square number.

1553291108721 is the 623156-th centered octagonal number.

It is an amenable number.

1553291108721 is a deficient number, since it is larger than the sum of its proper divisors (997377149802).

1553291108721 is an frugal number, since it uses more digits than its factorization.

1553291108721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25212 (or 12603 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 45.

The spelling of 1553291108721 in words is "one trillion, five hundred fifty-three billion, two hundred ninety-one million, one hundred eight thousand, seven hundred twenty-one".