1621218924 has 72 divisors (see below), whose sum is σ = 4418079120. Its totient is φ = 498298752.

The previous prime is 1621218829. The next prime is 1621218941. The reversal of 1621218924 is 4298121261.

1621218924 is a `hidden beast` number, since 1 + 621 + 2 + 1 + 8 + 9 + 24 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 798799 + ... + 800825.

It is an arithmetic number, because the mean of its divisors is an integer number (61362210).

Almost surely, 2^1621218924 is an apocalyptic number.

It is an amenable number.

1621218924 is an abundant number, since it is smaller than the sum of its proper divisors (2796860196).

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

1621218924 is a wasteful number, since it uses less digits than its factorization.

1621218924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3759 (or 3754 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1621218924 is about 40264.3629528644. The cubic root of 1621218924 is about 1174.7547818439.

The spelling of 1621218924 in words is "one billion, six hundred twenty-one million, two hundred eighteen thousand, nine hundred twenty-four".