21611473 has 8 divisors (see below), whose sum is σ = 23347688. Its totient is φ = 19885824.

The previous prime is 21611461. The next prime is 21611519. The reversal of 21611473 is 37411612.

It can be written as a sum of positive squares in 4 ways, for example, as 7569 + 21603904 = 87^2 + 4648^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21611473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21651473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1915 + ... + 6847.

It is an arithmetic number, because the mean of its divisors is an integer number (2918461).

Almost surely, 2^21611473 is an apocalyptic number.

It is an amenable number.

21611473 is a deficient number, since it is larger than the sum of its proper divisors (1736215).

21611473 is a wasteful number, since it uses less digits than its factorization.

21611473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5283.

The product of its digits is 1008, while the sum is 25.

The square root of 21611473 is about 4648.8141498666. The cubic root of 21611473 is about 278.5446295750.

The spelling of 21611473 in words is "twenty-one million, six hundred eleven thousand, four hundred seventy-three".