621561012 has 12 divisors (see below), whose sum is σ = 1450309056. Its totient is φ = 207187000.

The previous prime is 621561007. The next prime is 621561013. The reversal of 621561012 is 210165126.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621561013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25898364 + ... + 25898387.

It is an arithmetic number, because the mean of its divisors is an integer number (120859088).

Almost surely, 2^621561012 is an apocalyptic number.

It is an amenable number.

621561012 is an abundant number, since it is smaller than the sum of its proper divisors (828748044).

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

621561012 is a wasteful number, since it uses less digits than its factorization.

621561012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51796758 (or 51796756 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 621561012 is about 24931.1253656950. The cubic root of 621561012 is about 853.4169318462.

The spelling of 621561012 in words is "six hundred twenty-one million, five hundred sixty-one thousand, twelve".