621872081 has 2 divisors, whose sum is σ = 621872082. Its totient is φ = 621872080.

The previous prime is 621872077. The next prime is 621872093. The reversal of 621872081 is 180278126.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 330657856 + 291214225 = 18184^2 + 17065^2 .

It is a cyclic number.

It is not a de Polignac number, because 621872081 - 2² = 621872077 is a prime.

It is a super-2 number, since 2×621872081² = 773449770254541122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (621872011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310936040 + 310936041.

It is an arithmetic number, because the mean of its divisors is an integer number (310936041).

Almost surely, 2^621872081 is an apocalyptic number.

It is an amenable number.

621872081 is a deficient number, since it is larger than the sum of its proper divisors (1).

621872081 is an equidigital number, since it uses as much as digits as its factorization.

621872081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 621872081 is about 24937.3631525067. The cubic root of 621872081 is about 853.5592762942.

The spelling of 621872081 in words is "six hundred twenty-one million, eight hundred seventy-two thousand, eighty-one".