21952180285897 has 4 divisors (see below), whose sum is σ = 21952214453520. Its totient is φ = 21952146118276.

The previous prime is 21952180285873. The next prime is 21952180285939. The reversal of 21952180285897 is 79858208125912.

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 21952180285897 - 2⁴³ = 13156087263689 is a prime.

It is a super-4 number, since 4×21952180285897⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21952180285837) 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, 16101247 + ... + 17411332.

It is an arithmetic number, because the mean of its divisors is an integer number (5488053613380).

Almost surely, 2^{21952180285897} is an apocalyptic number.

It is an amenable number.

21952180285897 is a deficient number, since it is larger than the sum of its proper divisors (34167623).

21952180285897 is an equidigital number, since it uses as much as digits as its factorization.

21952180285897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34167622.

The product of its (nonzero) digits is 58060800, while the sum is 67.

The spelling of 21952180285897 in words is "twenty-one trillion, nine hundred fifty-two billion, one hundred eighty million, two hundred eighty-five thousand, eight hundred ninety-seven".