55721629 has 2 divisors, whose sum is σ = 55721630. Its totient is φ = 55721628.

The previous prime is 55721579. The next prime is 55721651. The reversal of 55721629 is 92612755.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41860900 + 13860729 = 6470^2 + 3723^2 .

It is a cyclic number.

It is not a de Polignac number, because 55721629 - 2⁹ = 55721117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55721669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860814 + 27860815.

It is an arithmetic number, because the mean of its divisors is an integer number (27860815).

Almost surely, 2^55721629 is an apocalyptic number.

It is an amenable number.

55721629 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721629 is an equidigital number, since it uses as much as digits as its factorization.

55721629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 37.

The square root of 55721629 is about 7464.6921570819. The cubic root of 55721629 is about 381.9512492267.

It can be divided in two parts, 55 and 721629, that multiplied together give a triangular number (39689595 = T₈₉₀₉).

The spelling of 55721629 in words is "fifty-five million, seven hundred twenty-one thousand, six hundred twenty-nine".