21877231 has 8 divisors (see below), whose sum is σ = 22889664. Its totient is φ = 20887680.

The previous prime is 21877199. The next prime is 21877241. The reversal of 21877231 is 13277812.

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 21877231 - 2⁵ = 21877199 is a prime.

It is a super-2 number, since 2×21877231² = 957226472454722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21877193 and 21877202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21877241) 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, 3750 + ... + 7603.

It is an arithmetic number, because the mean of its divisors is an integer number (2861208).

Almost surely, 2^21877231 is an apocalyptic number.

21877231 is a deficient number, since it is larger than the sum of its proper divisors (1012433).

21877231 is a wasteful number, since it uses less digits than its factorization.

21877231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11441.

The product of its digits is 4704, while the sum is 31.

The square root of 21877231 is about 4677.3102313189. The cubic root of 21877231 is about 279.6817429877.

The spelling of 21877231 in words is "twenty-one million, eight hundred seventy-seven thousand, two hundred thirty-one".