621896081 has 2 divisors, whose sum is σ = 621896082. Its totient is φ = 621896080.

The previous prime is 621896069. The next prime is 621896083. The reversal of 621896081 is 180698126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 556205056 + 65691025 = 23584^2 + 8105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621896081 is a prime.

It is a super-2 number, since 2×621896081² = 773509471126317122, which contains 22 as substring.

Together with 621896083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (621896083) 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, 310948040 + 310948041.

It is an arithmetic number, because the mean of its divisors is an integer number (310948041).

Almost surely, 2^621896081 is an apocalyptic number.

It is an amenable number.

621896081 is a deficient number, since it is larger than the sum of its proper divisors (1).

621896081 is an equidigital number, since it uses as much as digits as its factorization.

621896081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 621896081 is about 24937.8443535122. The cubic root of 621896081 is about 853.5702566656.

The spelling of 621896081 in words is "six hundred twenty-one million, eight hundred ninety-six thousand, eighty-one".