21173460461 has 4 divisors (see below), whose sum is σ = 21174125952. Its totient is φ = 21172794972.

The previous prime is 21173460421. The next prime is 21173460491. The reversal of 21173460461 is 16406437112.

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 21173460461 - 2¹⁴ = 21173444077 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 (21173460401) 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, 282491 + ... + 349496.

It is an arithmetic number, because the mean of its divisors is an integer number (5293531488).

Almost surely, 2^21173460461 is an apocalyptic number.

It is an amenable number.

21173460461 is a deficient number, since it is larger than the sum of its proper divisors (665491).

21173460461 is an equidigital number, since it uses as much as digits as its factorization.

21173460461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665490.

The product of its (nonzero) digits is 24192, while the sum is 35.

Adding to 21173460461 its reverse (16406437112), we get a palindrome (37579897573).

The spelling of 21173460461 in words is "twenty-one billion, one hundred seventy-three million, four hundred sixty thousand, four hundred sixty-one".