21754557 has 24 divisors (see below), whose sum is σ = 35212320. Its totient is φ = 12826080.

The previous prime is 21754541. The next prime is 21754567. The reversal of 21754557 is 75545712.

It is not a de Polignac number, because 21754557 - 2⁴ = 21754541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21754507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 694 + ... + 6632.

It is an arithmetic number, because the mean of its divisors is an integer number (1467180).

Almost surely, 2^21754557 is an apocalyptic number.

It is an amenable number.

21754557 is a deficient number, since it is larger than the sum of its proper divisors (13457763).

21754557 is a wasteful number, since it uses less digits than its factorization.

21754557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5993 (or 5990 counting only the distinct ones).

The product of its digits is 49000, while the sum is 36.

The square root of 21754557 is about 4664.1780626387. The cubic root of 21754557 is about 279.1580019983.

The spelling of 21754557 in words is "twenty-one million, seven hundred fifty-four thousand, five hundred fifty-seven".