21439692 has 18 divisors (see below), whose sum is σ = 54194868. Its totient is φ = 7146552.

The previous prime is 21439673. The next prime is 21439699. The reversal of 21439692 is 29693412.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 595547 = 21439692 / (2 + 1 + 4 + 3 + 9 + 6 + 9 + 2).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21439699) 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 5 ways as a sum of consecutive naturals, for example, 297738 + ... + 297809.

It is an arithmetic number, because the mean of its divisors is an integer number (3010826).

Almost surely, 2^21439692 is an apocalyptic number.

It is an amenable number.

21439692 is an abundant number, since it is smaller than the sum of its proper divisors (32755176).

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

21439692 is a wasteful number, since it uses less digits than its factorization.

21439692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 595557 (or 595552 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 21439692 is about 4630.3015020623. The cubic root of 21439692 is about 277.8046520251.

The spelling of 21439692 in words is "twenty-one million, four hundred thirty-nine thousand, six hundred ninety-two".