921134551 has 4 divisors (see below), whose sum is σ = 921196504. Its totient is φ = 921072600.

The previous prime is 921134509. The next prime is 921134561. The reversal of 921134551 is 155431129.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 155431129 = 7 ⋅22204447.

It is a 3-Lehmer number, since φ(921134551) divides (921134551-1)³.

It is a cyclic number.

It is not a de Polignac number, because 921134551 - 2²³ = 912745943 is a prime.

It is a super-2 number, since 2×921134551² = 1696977722091943202, which 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 (921134561) 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, 6196 + ... + 43366.

It is an arithmetic number, because the mean of its divisors is an integer number (230299126).

Almost surely, 2^921134551 is an apocalyptic number.

921134551 is the 24781-st pentagonal number.

921134551 is a deficient number, since it is larger than the sum of its proper divisors (61953).

921134551 is a wasteful number, since it uses less digits than its factorization.

921134551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61952.

The product of its digits is 5400, while the sum is 31.

The square root of 921134551 is about 30350.1985331233. The cubic root of 921134551 is about 972.9884632989.

The spelling of 921134551 in words is "nine hundred twenty-one million, one hundred thirty-four thousand, five hundred fifty-one".