21008763135 has 48 divisors (see below), whose sum is σ = 36663988608. Its totient is φ = 11128320000.

The previous prime is 21008763119. The next prime is 21008763173. The reversal of 21008763135 is 53136780012.

21008763135 is a `hidden beast` number, since 2 + 10 + 0 + 8 + 7 + 631 + 3 + 5 = 666.

It is a Cunningham number, because it is equal to 144944²-1.

It is not a de Polignac number, because 21008763135 - 2⁴ = 21008763119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21008763135.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6520825 + ... + 6524045.

It is an arithmetic number, because the mean of its divisors is an integer number (763833096).

Almost surely, 2^21008763135 is an apocalyptic number.

21008763135 is a deficient number, since it is larger than the sum of its proper divisors (15655225473).

21008763135 is a wasteful number, since it uses less digits than its factorization.

21008763135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4176 (or 4173 counting only the distinct ones).

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

The spelling of 21008763135 in words is "twenty-one billion, eight million, seven hundred sixty-three thousand, one hundred thirty-five".