21772605137551 has 4 divisors (see below), whose sum is σ = 21783764855104. Its totient is φ = 21761445420000.

The previous prime is 21772605137527. The next prime is 21772605137573. The reversal of 21772605137551 is 15573150627712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21772605137551 - 2²⁹ = 21772068266639 is a prime.

It is a super-3 number, since 3×21772605137551³ (a number of 41 digits) contains 333 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 (21772605137581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5579855850 + ... + 5579859751.

It is an arithmetic number, because the mean of its divisors is an integer number (5445941213776).

Almost surely, 2^{21772605137551} is an apocalyptic number.

21772605137551 is a deficient number, since it is larger than the sum of its proper divisors (11159717553).

21772605137551 is a wasteful number, since it uses less digits than its factorization.

21772605137551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11159717552.

The product of its (nonzero) digits is 3087000, while the sum is 52.

The spelling of 21772605137551 in words is "twenty-one trillion, seven hundred seventy-two billion, six hundred five million, one hundred thirty-seven thousand, five hundred fifty-one".