21437157695 has 4 divisors (see below), whose sum is σ = 25724589240. Its totient is φ = 17149726152.

The previous prime is 21437157691. The next prime is 21437157719. The reversal of 21437157695 is 59675173412.

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 21437157695 - 2² = 21437157691 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21437157691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2143715765 + ... + 2143715774.

It is an arithmetic number, because the mean of its divisors is an integer number (6431147310).

Almost surely, 2^21437157695 is an apocalyptic number.

21437157695 is a deficient number, since it is larger than the sum of its proper divisors (4287431545).

21437157695 is an equidigital number, since it uses as much as digits as its factorization.

21437157695 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4287431544.

The product of its digits is 1587600, while the sum is 50.

The spelling of 21437157695 in words is "twenty-one billion, four hundred thirty-seven million, one hundred fifty-seven thousand, six hundred ninety-five".