21053366805 has 16 divisors (see below), whose sum is σ = 34146832320. Its totient is φ = 11074647168.

The previous prime is 21053366801. The next prime is 21053366809. The reversal of 21053366805 is 50866335012.

It is an interprime number because it is at equal distance from previous prime (21053366801) and next prime (21053366809).

It is not a de Polignac number, because 21053366805 - 2² = 21053366801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053366801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9612315 + ... + 9614504.

It is an arithmetic number, because the mean of its divisors is an integer number (2134177020).

Almost surely, 2^21053366805 is an apocalyptic number.

It is an amenable number.

21053366805 is a deficient number, since it is larger than the sum of its proper divisors (13093465515).

21053366805 is a wasteful number, since it uses less digits than its factorization.

21053366805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19226900.

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 21053366805 in words is "twenty-one billion, fifty-three million, three hundred sixty-six thousand, eight hundred five".