21888870 has 32 divisors (see below), whose sum is σ = 54819072. Its totient is φ = 5583072.

The previous prime is 21888869. The next prime is 21888871. The reversal of 21888870 is 7888812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21888869) and next prime (21888871).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21888871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15172 + ... + 16551.

It is an arithmetic number, because the mean of its divisors is an integer number (1713096).

Almost surely, 2^21888870 is an apocalyptic number.

21888870 is an abundant number, since it is smaller than the sum of its proper divisors (32930202).

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

21888870 is a wasteful number, since it uses less digits than its factorization.

21888870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31756.

The product of its (nonzero) digits is 57344, while the sum is 42.

The square root of 21888870 is about 4678.5542638725. The cubic root of 21888870 is about 279.7313324247.

The spelling of 21888870 in words is "twenty-one million, eight hundred eighty-eight thousand, eight hundred seventy".