21557127 has 8 divisors (see below), whose sum is σ = 28787200. Its totient is φ = 14349240.

The previous prime is 21557113. The next prime is 21557143. The reversal of 21557127 is 72175512.

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

It is not a de Polignac number, because 21557127 - 2⁴ = 21557111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21557094 and 21557103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21557177) 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, 3127 + ... + 7272.

It is an arithmetic number, because the mean of its divisors is an integer number (3598400).

Almost surely, 2^21557127 is an apocalyptic number.

21557127 is a deficient number, since it is larger than the sum of its proper divisors (7230073).

21557127 is a wasteful number, since it uses less digits than its factorization.

21557127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11093.

The product of its digits is 4900, while the sum is 30.

The square root of 21557127 is about 4642.9653240144. The cubic root of 21557127 is about 278.3109497898.

The spelling of 21557127 in words is "twenty-one million, five hundred fifty-seven thousand, one hundred twenty-seven".