21139704 has 160 divisors (see below), whose sum is σ = 66646800. Its totient is φ = 6220800.

The previous prime is 21139667. The next prime is 21139709. The reversal of 21139704 is 40793112.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21139709) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 209254 + ... + 209354.

Almost surely, 2^21139704 is an apocalyptic number.

21139704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21139704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33323400).

21139704 is an abundant number, since it is smaller than the sum of its proper divisors (45507096).

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

21139704 is a wasteful number, since it uses less digits than its factorization.

21139704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21139704 is about 4597.7933837875. The cubic root of 21139704 is about 276.5028639584.

The spelling of 21139704 in words is "twenty-one million, one hundred thirty-nine thousand, seven hundred four".