21303751806 has 24 divisors (see below), whose sum is σ = 46495054944. Its totient is φ = 7049415840.

The previous prime is 21303751789. The next prime is 21303751867. The reversal of 21303751806 is 60815730312.

21303751806 is a `hidden beast` number, since 2 + 130 + 3 + 7 + 518 + 0 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4317030 + ... + 4321961.

It is an arithmetic number, because the mean of its divisors is an integer number (1937293956).

Almost surely, 2^21303751806 is an apocalyptic number.

21303751806 is an abundant number, since it is smaller than the sum of its proper divisors (25191303138).

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

21303751806 is a wasteful number, since it uses less digits than its factorization.

21303751806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8639136 (or 8639133 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21303751806 in words is "twenty-one billion, three hundred three million, seven hundred fifty-one thousand, eight hundred six".