21460531 has 4 divisors (see below), whose sum is σ = 21762864. Its totient is φ = 21158200.

The previous prime is 21460501. The next prime is 21460547. The reversal of 21460531 is 13506412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21460531 - 2⁵ = 21460499 is a prime.

It is a super-2 number, since 2×21460531² = 921108781603922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21460501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151060 + ... + 151201.

It is an arithmetic number, because the mean of its divisors is an integer number (5440716).

Almost surely, 2^21460531 is an apocalyptic number.

21460531 is a deficient number, since it is larger than the sum of its proper divisors (302333).

21460531 is an equidigital number, since it uses as much as digits as its factorization.

21460531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302332.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21460531 is about 4632.5512409470. The cubic root of 21460531 is about 277.8946299424.

Adding to 21460531 its reverse (13506412), we get a palindrome (34966943).

The spelling of 21460531 in words is "twenty-one million, four hundred sixty thousand, five hundred thirty-one".