21971862 has 24 divisors (see below), whose sum is σ = 51933960. Its totient is φ = 6658080.

The previous prime is 21971861. The next prime is 21971881. The reversal of 21971862 is 26817912.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21971861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55287 + ... + 55682.

It is an arithmetic number, because the mean of its divisors is an integer number (2163915).

Almost surely, 2^21971862 is an apocalyptic number.

21971862 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21971862 is an abundant number, since it is smaller than the sum of its proper divisors (29962098).

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

21971862 is a wasteful number, since it uses less digits than its factorization.

21971862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110988 (or 110985 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21971862 is about 4687.4152792344. The cubic root of 21971862 is about 280.0844218226.

The spelling of 21971862 in words is "twenty-one million, nine hundred seventy-one thousand, eight hundred sixty-two".