21907848169 has 3 divisors (see below), whose sum is σ = 21907996183. Its totient is φ = 21907700156.

The previous prime is 21907848143. The next prime is 21907848173. The reversal of 21907848169 is 96184870912.

It is a happy number.

The square root of 21907848169 is 148013.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2805291225 + 19102556944 = 52965^2 + 138212^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21907848169 is a prime.

It is a super-2 number, since 2×21907848169² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21907842169) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 74007 + ... + 222019.

Almost surely, 2^21907848169 is an apocalyptic number.

21907848169 is the 148013-rd square number.

21907848169 is the 74007-th centered octagonal number.

It is an amenable number.

21907848169 is a deficient number, since it is larger than the sum of its proper divisors (148014).

21907848169 is an frugal number, since it uses more digits than its factorization.

21907848169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296026 (or 148013 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 55.

The spelling of 21907848169 in words is "twenty-one billion, nine hundred seven million, eight hundred forty-eight thousand, one hundred sixty-nine".