623740639 has 4 divisors (see below), whose sum is σ = 623856520. Its totient is φ = 623624760.

The previous prime is 623740631. The next prime is 623740643. The reversal of 623740639 is 936047326.

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 623740639 - 2³ = 623740631 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 (623740631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49452 + ... + 60769.

It is an arithmetic number, because the mean of its divisors is an integer number (155964130).

Almost surely, 2^623740639 is an apocalyptic number.

623740639 is a deficient number, since it is larger than the sum of its proper divisors (115881).

623740639 is a wasteful number, since it uses less digits than its factorization.

623740639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115880.

The product of its (nonzero) digits is 163296, while the sum is 40.

The square root of 623740639 is about 24974.8000792799. The cubic root of 623740639 is about 854.4133266604.

The spelling of 623740639 in words is "six hundred twenty-three million, seven hundred forty thousand, six hundred thirty-nine".