21742955 has 8 divisors (see below), whose sum is σ = 28098672. Its totient is φ = 16056288.

The previous prime is 21742913. The next prime is 21742961. The reversal of 21742955 is 55924712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21742955 - 2²⁰ = 20694379 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 167189 + ... + 167318.

It is an arithmetic number, because the mean of its divisors is an integer number (3512334).

Almost surely, 2^21742955 is an apocalyptic number.

21742955 is a deficient number, since it is larger than the sum of its proper divisors (6355717).

21742955 is a wasteful number, since it uses less digits than its factorization.

21742955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334525.

The product of its digits is 25200, while the sum is 35.

The square root of 21742955 is about 4662.9341620915. The cubic root of 21742955 is about 279.1083669254.

The spelling of 21742955 in words is "twenty-one million, seven hundred forty-two thousand, nine hundred fifty-five".