21472737 has 16 divisors (see below), whose sum is σ = 33636288. Its totient is φ = 12012480.

The previous prime is 21472729. The next prime is 21472741. The reversal of 21472737 is 73727412.

It is not a de Polignac number, because 21472737 - 2³ = 21472729 is a prime.

It is a super-2 number, since 2×21472737² = 922156868542338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21472698 and 21472707.

It is not an unprimeable number, because it can be changed into a prime (21472727) 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 15 ways as a sum of consecutive naturals, for example, 24598 + ... + 25455.

It is an arithmetic number, because the mean of its divisors is an integer number (2102268).

Almost surely, 2^21472737 is an apocalyptic number.

It is an amenable number.

21472737 is a deficient number, since it is larger than the sum of its proper divisors (12163551).

21472737 is a wasteful number, since it uses less digits than its factorization.

21472737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50080.

The product of its digits is 16464, while the sum is 33.

The square root of 21472737 is about 4633.8684702956. The cubic root of 21472737 is about 277.9473055414.

It can be divided in two parts, 2147 and 2737, that added together give a palindrome (4884).

The spelling of 21472737 in words is "twenty-one million, four hundred seventy-two thousand, seven hundred thirty-seven".