21393080 has 16 divisors (see below), whose sum is σ = 48134520. Its totient is φ = 8557216.

The previous prime is 21393077. The next prime is 21393083. The reversal of 21393080 is 8039312.

It is an interprime number because it is at equal distance from previous prime (21393077) and next prime (21393083).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21393083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267374 + ... + 267453.

Almost surely, 2^21393080 is an apocalyptic number.

21393080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21393080 is an abundant number, since it is smaller than the sum of its proper divisors (26741440).

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

21393080 is a wasteful number, since it uses less digits than its factorization.

21393080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534838 (or 534834 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21393080 is about 4625.2653977907. The cubic root of 21393080 is about 277.6031810657.

The spelling of 21393080 in words is "twenty-one million, three hundred ninety-three thousand, eighty".