21011823825 has 12 divisors (see below), whose sum is σ = 34739548848. Its totient is φ = 11206306000.

The previous prime is 21011823809. The next prime is 21011823883. The reversal of 21011823825 is 52832811012.

It is not a de Polignac number, because 21011823825 - 2⁴ = 21011823809 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140078751 + ... + 140078900.

It is an arithmetic number, because the mean of its divisors is an integer number (2894962404).

Almost surely, 2^21011823825 is an apocalyptic number.

21011823825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21011823825 is a deficient number, since it is larger than the sum of its proper divisors (13727725023).

21011823825 is a wasteful number, since it uses less digits than its factorization.

21011823825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280157664 (or 280157659 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The spelling of 21011823825 in words is "twenty-one billion, eleven million, eight hundred twenty-three thousand, eight hundred twenty-five".