21739104 has 60 divisors (see below), whose sum is σ = 63941724. Its totient is φ = 7245504.

The previous prime is 21739103. The next prime is 21739129. The reversal of 21739104 is 40193712.

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 (21739103) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1602 + ... + 6785.

Almost surely, 2^21739104 is an apocalyptic number.

21739104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21739104 is an abundant number, since it is smaller than the sum of its proper divisors (42202620).

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

21739104 is an equidigital number, since it uses as much as digits as its factorization.

21739104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8409 (or 8392 counting only the distinct ones).

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

The square root of 21739104 is about 4662.5212063861. The cubic root of 21739104 is about 279.0918878745.

The spelling of 21739104 in words is "twenty-one million, seven hundred thirty-nine thousand, one hundred four".