21132401421 has 4 divisors (see below), whose sum is σ = 28176535232. Its totient is φ = 14088267612.

The previous prime is 21132401417. The next prime is 21132401467. The reversal of 21132401421 is 12410423112.

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 not a de Polignac number, because 21132401421 - 2² = 21132401417 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 (21132401401) 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, 3522066901 + ... + 3522066906.

It is an arithmetic number, because the mean of its divisors is an integer number (7044133808).

Almost surely, 2^21132401421 is an apocalyptic number.

It is an amenable number.

21132401421 is a deficient number, since it is larger than the sum of its proper divisors (7044133811).

21132401421 is an equidigital number, since it uses as much as digits as its factorization.

21132401421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7044133810.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21132401421 its reverse (12410423112), we get a palindrome (33542824533).

The spelling of 21132401421 in words is "twenty-one billion, one hundred thirty-two million, four hundred one thousand, four hundred twenty-one".