21049735655 has 16 divisors (see below), whose sum is σ = 27410400864. Its totient is φ = 15425754240.

The previous prime is 21049735649. The next prime is 21049735697. The reversal of 21049735655 is 55653794012.

It is not a de Polignac number, because 21049735655 - 2⁶ = 21049735591 is a prime.

It is a super-2 number, since 2×21049735655² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1227524 + ... + 1244553.

It is an arithmetic number, because the mean of its divisors is an integer number (1713150054).

Almost surely, 2^21049735655 is an apocalyptic number.

21049735655 is a deficient number, since it is larger than the sum of its proper divisors (6360665209).

21049735655 is a wasteful number, since it uses less digits than its factorization.

21049735655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2472226.

The product of its (nonzero) digits is 1134000, while the sum is 47.

The spelling of 21049735655 in words is "twenty-one billion, forty-nine million, seven hundred thirty-five thousand, six hundred fifty-five".