21927155 has 8 divisors (see below), whose sum is σ = 26568672. Its totient is φ = 17371008.

The previous prime is 21927151. The next prime is 21927181. The reversal of 21927155 is 55172912.

It is a happy number.

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 21927155 - 2² = 21927151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21927151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20774 + ... + 21803.

It is an arithmetic number, because the mean of its divisors is an integer number (3321084).

Almost surely, 2^21927155 is an apocalyptic number.

21927155 is a deficient number, since it is larger than the sum of its proper divisors (4641517).

21927155 is a wasteful number, since it uses less digits than its factorization.

21927155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42685.

The product of its digits is 6300, while the sum is 32.

The square root of 21927155 is about 4682.6440180735. The cubic root of 21927155 is about 279.8943266200.

The spelling of 21927155 in words is "twenty-one million, nine hundred twenty-seven thousand, one hundred fifty-five".