621931634 has 4 divisors (see below), whose sum is σ = 932897454. Its totient is φ = 310965816.

The previous prime is 621931633. The next prime is 621931643. The reversal of 621931634 is 436139126.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 436139126 = 2 ⋅218069563.

It can be written as a sum of positive squares in only one way, i.e., 617373409 + 4558225 = 24847^2 + 2135^2 .

It is a junction number, because it is equal to n+sod(n) for n = 621931594 and 621931603.

It is not an unprimeable number, because it can be changed into a prime (621931633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155482907 + ... + 155482910.

Almost surely, 2^621931634 is an apocalyptic number.

621931634 is a deficient number, since it is larger than the sum of its proper divisors (310965820).

621931634 is a wasteful number, since it uses less digits than its factorization.

621931634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310965819.

The product of its digits is 23328, while the sum is 35.

The square root of 621931634 is about 24938.5571755866. The cubic root of 621931634 is about 853.5865221939.

The spelling of 621931634 in words is "six hundred twenty-one million, nine hundred thirty-one thousand, six hundred thirty-four".