21471772 has 24 divisors (see below), whose sum is σ = 43112160. Its totient is φ = 9166080.

The previous prime is 21471757. The next prime is 21471773. The reversal of 21471772 is 27717412.

It is a super-2 number, since 2×21471772² = 922073985639968, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471773) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 6504 + ... + 9232.

It is an arithmetic number, because the mean of its divisors is an integer number (1796340).

Almost surely, 2^21471772 is an apocalyptic number.

It is an amenable number.

21471772 is an abundant number, since it is smaller than the sum of its proper divisors (21640388).

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

21471772 is a wasteful number, since it uses less digits than its factorization.

21471772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3021 (or 3019 counting only the distinct ones).

The product of its digits is 5488, while the sum is 31.

The square root of 21471772 is about 4633.7643444612. The cubic root of 21471772 is about 277.9431417628.

The spelling of 21471772 in words is "twenty-one million, four hundred seventy-one thousand, seven hundred seventy-two".