21974890 has 32 divisors (see below), whose sum is σ = 47174400. Its totient is φ = 7206144.

The previous prime is 21974881. The next prime is 21974899. The reversal of 21974890 is 9847912.

It is an interprime number because it is at equal distance from previous prime (21974881) and next prime (21974899).

It is not an unprimeable number, because it can be changed into a prime (21974899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5215 + ... + 8434.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21974890 is an apocalyptic number.

21974890 is an abundant number, since it is smaller than the sum of its proper divisors (25199510).

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

21974890 is a wasteful number, since it uses less digits than its factorization.

21974890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13686.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 21974890 is about 4687.7382606114. The cubic root of 21974890 is about 280.0972876215.

The spelling of 21974890 in words is "twenty-one million, nine hundred seventy-four thousand, eight hundred ninety".