21407488 has 36 divisors (see below), whose sum is σ = 45254160. Its totient is φ = 10072064.

The previous prime is 21407479. The next prime is 21407521. The reversal of 21407488 is 88470412.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1893 + ... + 6811.

It is an arithmetic number, because the mean of its divisors is an integer number (1257060).

Almost surely, 2^21407488 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21407488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22627080).

21407488 is an abundant number, since it is smaller than the sum of its proper divisors (23846672).

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

21407488 is an equidigital number, since it uses as much as digits as its factorization.

21407488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4952 (or 4938 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 21407488 is about 4626.8226678791. The cubic root of 21407488 is about 277.6654879589.

The spelling of 21407488 in words is "twenty-one million, four hundred seven thousand, four hundred eighty-eight".