21429253191 has 4 divisors (see below), whose sum is σ = 28572337592. Its totient is φ = 14286168792.

The previous prime is 21429253187. The next prime is 21429253201. The reversal of 21429253191 is 19135292412.

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

It is not a de Polignac number, because 21429253191 - 2² = 21429253187 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 (21429253121) 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, 3571542196 + ... + 3571542201.

It is an arithmetic number, because the mean of its divisors is an integer number (7143084398).

Almost surely, 2^21429253191 is an apocalyptic number.

21429253191 is a deficient number, since it is larger than the sum of its proper divisors (7143084401).

21429253191 is an equidigital number, since it uses as much as digits as its factorization.

21429253191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143084400.

The product of its digits is 38880, while the sum is 39.

The spelling of 21429253191 in words is "twenty-one billion, four hundred twenty-nine million, two hundred fifty-three thousand, one hundred ninety-one".