20943993915 has 24 divisors (see below), whose sum is σ = 39095456400. Its totient is φ = 10310889024.

The previous prime is 20943993901. The next prime is 20943993947. The reversal of 20943993915 is 51939934902.

20943993915 is a `hidden beast` number, since 209 + 4 + 399 + 39 + 15 = 666.

It is not a de Polignac number, because 20943993915 - 2⁷ = 20943993787 is a prime.

It is a super-2 number, since 2×20943993915² (a number of 21 digits) contains 22 as substring.

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, 17900265 + ... + 17901434.

It is an arithmetic number, because the mean of its divisors is an integer number (1628977350).

Almost surely, 2^20943993915 is an apocalyptic number.

20943993915 is a deficient number, since it is larger than the sum of its proper divisors (18151462485).

20943993915 is a wasteful number, since it uses less digits than its factorization.

20943993915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35801723 (or 35801720 counting only the distinct ones).

The product of its (nonzero) digits is 2361960, while the sum is 54.

The spelling of 20943993915 in words is "twenty billion, nine hundred forty-three million, nine hundred ninety-three thousand, nine hundred fifteen".