21137782855 has 16 divisors (see below), whose sum is σ = 28993884480. Its totient is φ = 14492017152.

The previous prime is 21137782843. The next prime is 21137782859. The reversal of 21137782855 is 55828773112.

It is a cyclic number.

It is not a de Polignac number, because 21137782855 - 2¹⁷ = 21137651783 is a prime.

It is a super-3 number, since 3×21137782855³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21137782799 and 21137782808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21137782859) 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, 171247 + ... + 267583.

It is an arithmetic number, because the mean of its divisors is an integer number (1812117780).

Almost surely, 2^21137782855 is an apocalyptic number.

21137782855 is a deficient number, since it is larger than the sum of its proper divisors (7856101625).

21137782855 is an equidigital number, since it uses as much as digits as its factorization.

21137782855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102618.

The product of its digits is 940800, while the sum is 49.

The spelling of 21137782855 in words is "twenty-one billion, one hundred thirty-seven million, seven hundred eighty-two thousand, eight hundred fifty-five".