621244840 has 16 divisors (see below), whose sum is σ = 1397800980. Its totient is φ = 248497920.

The previous prime is 621244823. The next prime is 621244847. The reversal of 621244840 is 48442126.

It can be written as a sum of positive squares in 2 ways, for example, as 611770756 + 9474084 = 24734^2 + 3078^2 .

It is not an unprimeable number, because it can be changed into a prime (621244847) 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, 7765521 + ... + 7765600.

Almost surely, 2^621244840 is an apocalyptic number.

It is an amenable number.

621244840 is an abundant number, since it is smaller than the sum of its proper divisors (776556140).

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

621244840 is a wasteful number, since it uses less digits than its factorization.

621244840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15531132 (or 15531128 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 31.

The square root of 621244840 is about 24924.7836500139. The cubic root of 621244840 is about 853.2722036017.

Adding to 621244840 its reverse (48442126), we get a palindrome (669686966).

The spelling of 621244840 in words is "six hundred twenty-one million, two hundred forty-four thousand, eight hundred forty".