21877136 has 20 divisors (see below), whose sum is σ = 43849500. Its totient is φ = 10561152.

The previous prime is 21877133. The next prime is 21877157. The reversal of 21877136 is 63177812.

It can be written as a sum of positive squares in 2 ways, for example, as 3763600 + 18113536 = 1940^2 + 4256^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21877096 and 21877105.

It is not an unprimeable number, because it can be changed into a prime (21877133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23111 + ... + 24038.

It is an arithmetic number, because the mean of its divisors is an integer number (2192475).

Almost surely, 2^21877136 is an apocalyptic number.

It is an amenable number.

21877136 is an abundant number, since it is smaller than the sum of its proper divisors (21972364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21877136 is a wasteful number, since it uses less digits than its factorization.

21877136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47186 (or 47180 counting only the distinct ones).

The product of its digits is 14112, while the sum is 35.

The square root of 21877136 is about 4677.3000758985. The cubic root of 21877136 is about 279.6813381558.

The spelling of 21877136 in words is "twenty-one million, eight hundred seventy-seven thousand, one hundred thirty-six".