621207440 has 80 divisors (see below), whose sum is σ = 1653965568. Its totient is φ = 212556288.

The previous prime is 621207427. The next prime is 621207449. The reversal of 621207440 is 44702126.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×621207440² = 771797367022707200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (621207449) 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, 415334 + ... + 416826.

Almost surely, 2^621207440 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 621207440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (826982784).

621207440 is an abundant number, since it is smaller than the sum of its proper divisors (1032758128).

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

621207440 is a wasteful number, since it uses less digits than its factorization.

621207440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2256 (or 2250 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 621207440 is about 24924.0333814573. The cubic root of 621207440 is about 853.2550804436.

Adding to 621207440 its reverse (44702126), we get a palindrome (665909566).

The spelling of 621207440 in words is "six hundred twenty-one million, two hundred seven thousand, four hundred forty".