11553553021 has 2 divisors, whose sum is σ = 11553553022. Its totient is φ = 11553553020.

The previous prime is 11553553009. The next prime is 11553553043. The reversal of 11553553021 is 12035535511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11424616996 + 128936025 = 106886^2 + 11355^2 .

It is a cyclic number.

It is not a de Polignac number, because 11553553021 - 2¹¹ = 11553550973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11553553321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5776776510 + 5776776511.

It is an arithmetic number, because the mean of its divisors is an integer number (5776776511).

Almost surely, 2^11553553021 is an apocalyptic number.

It is an amenable number.

11553553021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11553553021 is an equidigital number, since it uses as much as digits as its factorization.

11553553021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11250, while the sum is 31.

The spelling of 11553553021 in words is "eleven billion, five hundred fifty-three million, five hundred fifty-three thousand, twenty-one".