21293460 has 36 divisors (see below), whose sum is σ = 64590708. Its totient is φ = 5678208.

The previous prime is 21293431. The next prime is 21293483. The reversal of 21293460 is 6439212.

It can be written as a sum of positive squares in 2 ways, for example, as 3196944 + 18096516 = 1788^2 + 4254^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21293460² = 906822877543200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58969 + ... + 59328.

Almost surely, 2^21293460 is an apocalyptic number.

21293460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21293460 is an abundant number, since it is smaller than the sum of its proper divisors (43297248).

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

21293460 is a wasteful number, since it uses less digits than its factorization.

21293460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118312 (or 118307 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21293460 is about 4614.4837197676. The cubic root of 21293460 is about 277.1716105681.

The spelling of 21293460 in words is "twenty-one million, two hundred ninety-three thousand, four hundred sixty".