620515621 has 4 divisors (see below), whose sum is σ = 676926144. Its totient is φ = 564105100.

The previous prime is 620515591. The next prime is 620515627. The reversal of 620515621 is 126515026.

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 620515621 - 2⁹ = 620515109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 620515621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620515627) 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, 28205245 + ... + 28205266.

It is an arithmetic number, because the mean of its divisors is an integer number (169231536).

Almost surely, 2^620515621 is an apocalyptic number.

It is an amenable number.

620515621 is a deficient number, since it is larger than the sum of its proper divisors (56410523).

620515621 is a wasteful number, since it uses less digits than its factorization.

620515621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56410522.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 620515621 is about 24910.1509630110. The cubic root of 620515621 is about 852.9382150906.

The spelling of 620515621 in words is "six hundred twenty million, five hundred fifteen thousand, six hundred twenty-one".