621156540 has 48 divisors (see below), whose sum is σ = 1841549472. Its totient is φ = 155897856.

The previous prime is 621156521. The next prime is 621156541. The reversal of 621156540 is 45651126.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 621156498 and 621156507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621156541) 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, 303469 + ... + 305508.

It is an arithmetic number, because the mean of its divisors is an integer number (38365614).

Almost surely, 2^621156540 is an apocalyptic number.

621156540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

621156540 is an abundant number, since it is smaller than the sum of its proper divisors (1220392932).

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

621156540 is a wasteful number, since it uses less digits than its factorization.

621156540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609006 (or 609004 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 621156540 is about 24923.0122577509. The cubic root of 621156540 is about 853.2317753622.

The spelling of 621156540 in words is "six hundred twenty-one million, one hundred fifty-six thousand, five hundred forty".