620640421 has 8 divisors (see below), whose sum is σ = 627631200. Its totient is φ = 613686000.

The previous prime is 620640389. The next prime is 620640481. The reversal of 620640421 is 124046026.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 620640421 - 2⁵ = 620640389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620640481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25995 + ... + 43783.

It is an arithmetic number, because the mean of its divisors is an integer number (78453900).

Almost surely, 2^620640421 is an apocalyptic number.

It is an amenable number.

620640421 is a deficient number, since it is larger than the sum of its proper divisors (6990779).

620640421 is a wasteful number, since it uses less digits than its factorization.

620640421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18179.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 620640421 is about 24912.6558399541. The cubic root of 620640421 is about 852.9953931052.

Adding to 620640421 its reverse (124046026), we get a palindrome (744686447).

The spelling of 620640421 in words is "six hundred twenty million, six hundred forty thousand, four hundred twenty-one".