621955137211 has 4 divisors (see below), whose sum is σ = 638764735552. Its totient is φ = 605145538872.

The previous prime is 621955137203. The next prime is 621955137283. The reversal of 621955137211 is 112731559126.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 621955137211 - 2³ = 621955137203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621955137311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8404799115 + ... + 8404799188.

It is an arithmetic number, because the mean of its divisors is an integer number (159691183888).

Almost surely, 2^621955137211 is an apocalyptic number.

621955137211 is a deficient number, since it is larger than the sum of its proper divisors (16809598341).

621955137211 is a wasteful number, since it uses less digits than its factorization.

621955137211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16809598340.

The product of its digits is 113400, while the sum is 43.

The spelling of 621955137211 in words is "six hundred twenty-one billion, nine hundred fifty-five million, one hundred thirty-seven thousand, two hundred eleven".