621407861 has 4 divisors (see below), whose sum is σ = 621516672. Its totient is φ = 621299052.

The previous prime is 621407827. The next prime is 621407873. The reversal of 621407861 is 168704126.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 621407861 - 2⁶ = 621407797 is a prime.

It is a super-2 number, since 2×621407861² = 772295459425190642, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621407161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45335 + ... + 57428.

It is an arithmetic number, because the mean of its divisors is an integer number (155379168).

Almost surely, 2^621407861 is an apocalyptic number.

It is an amenable number.

621407861 is a deficient number, since it is larger than the sum of its proper divisors (108811).

621407861 is a wasteful number, since it uses less digits than its factorization.

621407861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108810.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 621407861 is about 24928.0536945827. The cubic root of 621407861 is about 853.3468328587.

The spelling of 621407861 in words is "six hundred twenty-one million, four hundred seven thousand, eight hundred sixty-one".