621125820 has 120 divisors (see below), whose sum is σ = 2226891744. Its totient is φ = 141969024.

The previous prime is 621125819. The next prime is 621125837. The reversal of 621125820 is 28521126.

It is a happy number.

621125820 is a `hidden beast` number, since 621 + 12 + 5 + 8 + 20 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 16047 + ... + 38726.

Almost surely, 2^621125820 is an apocalyptic number.

621125820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

621125820 is an abundant number, since it is smaller than the sum of its proper divisors (1605765924).

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

621125820 is a wasteful number, since it uses less digits than its factorization.

621125820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54801 (or 54790 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 621125820 is about 24922.3959522354. The cubic root of 621125820 is about 853.2177092825.

Adding to 621125820 its reverse (28521126), we get a palindrome (649646946).

The spelling of 621125820 in words is "six hundred twenty-one million, one hundred twenty-five thousand, eight hundred twenty".