21731461 has 4 divisors (see below), whose sum is σ = 21746592. Its totient is φ = 21716332.

The previous prime is 21731453. The next prime is 21731473. The reversal of 21731461 is 16413712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21731461 - 2³ = 21731453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21731441) 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 3 ways as a sum of consecutive naturals, for example, 5155 + ... + 8368.

It is an arithmetic number, because the mean of its divisors is an integer number (5436648).

Almost surely, 2^21731461 is an apocalyptic number.

It is an amenable number.

21731461 is a deficient number, since it is larger than the sum of its proper divisors (15131).

21731461 is a wasteful number, since it uses less digits than its factorization.

21731461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15130.

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

The square root of 21731461 is about 4661.7015133962. The cubic root of 21731461 is about 279.0591764783.

The spelling of 21731461 in words is "twenty-one million, seven hundred thirty-one thousand, four hundred sixty-one".