55515532421 has 2 divisors, whose sum is σ = 55515532422. Its totient is φ = 55515532420.

The previous prime is 55515532409. The next prime is 55515532433. The reversal of 55515532421 is 12423551555.

It is a balanced prime because it is at equal distance from previous prime (55515532409) and next prime (55515532433).

It can be written as a sum of positive squares in only one way, i.e., 33288002500 + 22227529921 = 182450^2 + 149089^2 .

It is a cyclic number.

It is not a de Polignac number, because 55515532421 - 2³⁴ = 38335663237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55515532441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27757766210 + 27757766211.

It is an arithmetic number, because the mean of its divisors is an integer number (27757766211).

Almost surely, 2^55515532421 is an apocalyptic number.

It is an amenable number.

55515532421 is a deficient number, since it is larger than the sum of its proper divisors (1).

55515532421 is an equidigital number, since it uses as much as digits as its factorization.

55515532421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 150000, while the sum is 38.

The spelling of 55515532421 in words is "fifty-five billion, five hundred fifteen million, five hundred thirty-two thousand, four hundred twenty-one".