621688402 has 8 divisors (see below), whose sum is σ = 987387516. Its totient is φ = 292559232.

The previous prime is 621688391. The next prime is 621688409. The reversal of 621688402 is 204886126.

It can be written as a sum of positive squares in 2 ways, for example, as 480530241 + 141158161 = 21921^2 + 11881^2 .

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

It is not an unprimeable number, because it can be changed into a prime (621688409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9142443 + ... + 9142510.

Almost surely, 2^621688402 is an apocalyptic number.

621688402 is a deficient number, since it is larger than the sum of its proper divisors (365699114).

621688402 is a wasteful number, since it uses less digits than its factorization.

621688402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18284972.

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 621688402 is about 24933.6800733466. The cubic root of 621688402 is about 853.4752309536.

The spelling of 621688402 in words is "six hundred twenty-one million, six hundred eighty-eight thousand, four hundred two".