55538621 has 2 divisors, whose sum is σ = 55538622. Its totient is φ = 55538620.

The previous prime is 55538617. The next prime is 55538627. The reversal of 55538621 is 12683555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32604100 + 22934521 = 5710^2 + 4789^2 .

It is a cyclic number.

It is not a de Polignac number, because 55538621 - 2² = 55538617 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55538627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27769310 + 27769311.

It is an arithmetic number, because the mean of its divisors is an integer number (27769311).

Almost surely, 2^55538621 is an apocalyptic number.

It is an amenable number.

55538621 is a deficient number, since it is larger than the sum of its proper divisors (1).

55538621 is an equidigital number, since it uses as much as digits as its factorization.

55538621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 35.

The square root of 55538621 is about 7452.4238338946. The cubic root of 55538621 is about 381.5326397905.

The spelling of 55538621 in words is "fifty-five million, five hundred thirty-eight thousand, six hundred twenty-one".