21713480 has 16 divisors (see below), whose sum is σ = 48855420. Its totient is φ = 8685376.

The previous prime is 21713479. The next prime is 21713491. The reversal of 21713480 is 8431712.

It can be written as a sum of positive squares in 2 ways, for example, as 21585316 + 128164 = 4646^2 + 358^2 .

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, 271379 + ... + 271458.

Almost surely, 2^21713480 is an apocalyptic number.

21713480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21713480 is an abundant number, since it is smaller than the sum of its proper divisors (27141940).

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

21713480 is a wasteful number, since it uses less digits than its factorization.

21713480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542848 (or 542844 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21713480 is about 4659.7725266369. The cubic root of 21713480 is about 278.9821890541.

The spelling of 21713480 in words is "twenty-one million, seven hundred thirteen thousand, four hundred eighty".