21472740 has 36 divisors (see below), whose sum is σ = 65134524. Its totient is φ = 5726016.

The previous prime is 21472729. The next prime is 21472741. The reversal of 21472740 is 4727412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4875264 + 16597476 = 2208^2 + 4074^2 .

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

It is a super-2 number, since 2×21472740² = 922157126215200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21472741) 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 11 ways as a sum of consecutive naturals, for example, 59467 + ... + 59826.

Almost surely, 2^21472740 is an apocalyptic number.

21472740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21472740 is an abundant number, since it is smaller than the sum of its proper divisors (43661784).

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

21472740 is a wasteful number, since it uses less digits than its factorization.

21472740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119308 (or 119303 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 21472740 is about 4633.8687939992. The cubic root of 21472740 is about 277.9473184855.

The spelling of 21472740 in words is "twenty-one million, four hundred seventy-two thousand, seven hundred forty".