21320478 has 12 divisors (see below), whose sum is σ = 46194408. Its totient is φ = 7106820.

The previous prime is 21320447. The next prime is 21320479. The reversal of 21320478 is 87402312.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320479) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 592218 + ... + 592253.

It is an arithmetic number, because the mean of its divisors is an integer number (3849534).

Almost surely, 2^21320478 is an apocalyptic number.

21320478 is an abundant number, since it is smaller than the sum of its proper divisors (24873930).

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

21320478 is a wasteful number, since it uses less digits than its factorization.

21320478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184479 (or 1184476 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21320478 is about 4617.4103131517. The cubic root of 21320478 is about 277.2887898572.

The spelling of 21320478 in words is "twenty-one million, three hundred twenty thousand, four hundred seventy-eight".