921725755 has 4 divisors (see below), whose sum is σ = 1106070912. Its totient is φ = 737380600.

The previous prime is 921725729. The next prime is 921725773. The reversal of 921725755 is 557527129.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 557527129 = 61 ⋅9139789.

It is a de Polignac number, because none of the positive numbers 2^k-921725755 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92172571 + ... + 92172580.

It is an arithmetic number, because the mean of its divisors is an integer number (276517728).

Almost surely, 2^921725755 is an apocalyptic number.

921725755 is a deficient number, since it is larger than the sum of its proper divisors (184345157).

921725755 is a wasteful number, since it uses less digits than its factorization.

921725755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184345156.

The product of its digits is 220500, while the sum is 43.

The square root of 921725755 is about 30359.9366764821. The cubic root of 921725755 is about 973.1965804332.

The spelling of 921725755 in words is "nine hundred twenty-one million, seven hundred twenty-five thousand, seven hundred fifty-five".