21402077591 has 16 divisors (see below), whose sum is σ = 22265324928. Its totient is φ = 20557363200.

The previous prime is 21402077581. The next prime is 21402077611. The reversal of 21402077591 is 19577020412.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21402077591 - 2²⁶ = 21334968727 is a prime.

It is a super-2 number, since 2×21402077591² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402077561) 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, 1313591 + ... + 1329783.

It is an arithmetic number, because the mean of its divisors is an integer number (1391582808).

Almost surely, 2^21402077591 is an apocalyptic number.

21402077591 is a deficient number, since it is larger than the sum of its proper divisors (863247337).

21402077591 is a wasteful number, since it uses less digits than its factorization.

21402077591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16762.

The product of its (nonzero) digits is 35280, while the sum is 38.

The spelling of 21402077591 in words is "twenty-one billion, four hundred two million, seventy-seven thousand, five hundred ninety-one".