21473971600 has 135 divisors (see below), whose sum is σ = 54931962211. Its totient is φ = 8065561600.

The previous prime is 21473971579. The next prime is 21473971601. The reversal of 21473971600 is 617937412.

The square root of 21473971600 is 146540.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 502297744 + 20971673856 = 22412^2 + 144816^2 .

It is a super-2 number, since 2×21473971600² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21473971601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 49823385 + ... + 49823815.

Almost surely, 2^21473971600 is an apocalyptic number.

21473971600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21473971600 is the 146540-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21473971600

21473971600 is an abundant number, since it is smaller than the sum of its proper divisors (33457990611).

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

21473971600 is an equidigital number, since it uses as much as digits as its factorization.

21473971600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 40.

The spelling of 21473971600 in words is "twenty-one billion, four hundred seventy-three million, nine hundred seventy-one thousand, six hundred".