195400379921 has 4 divisors (see below), whose sum is σ = 195567247344. Its totient is φ = 195233512500.

The previous prime is 195400379849. The next prime is 195400379959. The reversal of 195400379921 is 129973004591.

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 195400379921 - 2¹⁰ = 195400378897 is a prime.

It is a super-2 number, since 2×195400379921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 195400379921.

It is not an unprimeable number, because it can be changed into a prime (195400379981) 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, 83431955 + ... + 83434296.

It is an arithmetic number, because the mean of its divisors is an integer number (48891811836).

Almost surely, 2^195400379921 is an apocalyptic number.

It is an amenable number.

195400379921 is a deficient number, since it is larger than the sum of its proper divisors (166867423).

195400379921 is a wasteful number, since it uses less digits than its factorization.

195400379921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166867422.

The product of its (nonzero) digits is 612360, while the sum is 50.

The spelling of 195400379921 in words is "one hundred ninety-five billion, four hundred million, three hundred seventy-nine thousand, nine hundred twenty-one".