621666396 has 144 divisors (see below), whose sum is σ = 1797053440. Its totient is φ = 179625600.

The previous prime is 621666347. The next prime is 621666427. The reversal of 621666396 is 693666126.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1342461 + ... + 1342923.

Almost surely, 2^621666396 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621666396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (898526720).

621666396 is an abundant number, since it is smaller than the sum of its proper divisors (1175387044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621666396 is a wasteful number, since it uses less digits than its factorization.

621666396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 651 counting only the distinct ones).

The product of its digits is 419904, while the sum is 45.

The square root of 621666396 is about 24933.2387787868. The cubic root of 621666396 is about 853.4651606367.

The spelling of 621666396 in words is "six hundred twenty-one million, six hundred sixty-six thousand, three hundred ninety-six".