21700780311 has 32 divisors (see below), whose sum is σ = 33416179200. Its totient is φ = 12269980800.

The previous prime is 21700780291. The next prime is 21700780319. The reversal of 21700780311 is 11308700712.

It is not a de Polignac number, because 21700780311 - 2¹⁴ = 21700763927 is a prime.

It is a super-2 number, since 2×21700780311² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700780319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6401605 + ... + 6404993.

It is an arithmetic number, because the mean of its divisors is an integer number (1044255600).

Almost surely, 2^21700780311 is an apocalyptic number.

21700780311 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21700780311 is a deficient number, since it is larger than the sum of its proper divisors (11715398889).

21700780311 is a wasteful number, since it uses less digits than its factorization.

21700780311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6519.

The product of its (nonzero) digits is 2352, while the sum is 30.

It can be divided in two parts, 21700 and 780311, that added together give a triangular number (802011 = T₁₂₆₆).

The spelling of 21700780311 in words is "twenty-one billion, seven hundred million, seven hundred eighty thousand, three hundred eleven".