55721401 has 2 divisors, whose sum is σ = 55721402. Its totient is φ = 55721400.

The previous prime is 55721399. The next prime is 55721417. The reversal of 55721401 is 10412755.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39075001 + 16646400 = 6251^2 + 4080^2 .

It is a cyclic number.

It is not a de Polignac number, because 55721401 - 2¹ = 55721399 is a prime.

Together with 55721399, it forms a pair of twin primes.

It is equal to p_3322690 and since 55721401 and 3322690 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (55721201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860700 + 27860701.

It is an arithmetic number, because the mean of its divisors is an integer number (27860701).

Almost surely, 2^55721401 is an apocalyptic number.

It is an amenable number.

55721401 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721401 is an equidigital number, since it uses as much as digits as its factorization.

55721401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 55721401 is about 7464.6768851706. The cubic root of 55721401 is about 381.9507282740.

The spelling of 55721401 in words is "fifty-five million, seven hundred twenty-one thousand, four hundred one".