21361635255 has 16 divisors (see below), whose sum is σ = 34214730624. Its totient is φ = 11380834080.

The previous prime is 21361635221. The next prime is 21361635283. The reversal of 21361635255 is 55253616312.

It is not a de Polignac number, because 21361635255 - 2⁸ = 21361634999 is a prime.

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, 737701 + ... + 766110.

It is an arithmetic number, because the mean of its divisors is an integer number (2138420664).

Almost surely, 2^21361635255 is an apocalyptic number.

21361635255 is a deficient number, since it is larger than the sum of its proper divisors (12853095369).

21361635255 is a wasteful number, since it uses less digits than its factorization.

21361635255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1504766.

The product of its digits is 162000, while the sum is 39.

The spelling of 21361635255 in words is "twenty-one billion, three hundred sixty-one million, six hundred thirty-five thousand, two hundred fifty-five".