621213408 has 96 divisors (see below), whose sum is σ = 1874426400. Its totient is φ = 199922688.

The previous prime is 621213407. The next prime is 621213469. The reversal of 621213408 is 804312126.

621213408 is a `hidden beast` number, since 621 + 2 + 1 + 34 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621213401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12660 + ... + 37452.

It is an arithmetic number, because the mean of its divisors is an integer number (19525275).

Almost surely, 2^621213408 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 621213408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (937213200).

621213408 is an abundant number, since it is smaller than the sum of its proper divisors (1253212992).

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

621213408 is a wasteful number, since it uses less digits than its factorization.

621213408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24841 (or 24827 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 621213408 is about 24924.1531049703. The cubic root of 621213408 is about 853.2578128695.

The spelling of 621213408 in words is "six hundred twenty-one million, two hundred thirteen thousand, four hundred eight".