123721428195 has 12 divisors (see below), whose sum is σ = 214450475616. Its totient is φ = 65984761680.

The previous prime is 123721428179. The next prime is 123721428199. The reversal of 123721428195 is 591824127321.

123721428195 is a `hidden beast` number, since 1 + 2 + 37 + 2 + 1 + 428 + 195 = 666.

It is not a de Polignac number, because 123721428195 - 2⁴ = 123721428179 is a prime.

It is a super-2 number, since 2×123721428195² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 2749365071 = 123721428195 / (1 + 2 + 3 + 7 + 2 + 1 + 4 + 2 + 8 + 1 + 9 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 123721428195.

It is not an unprimeable number, because it can be changed into a prime (123721428199) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1374682491 + ... + 1374682580.

It is an arithmetic number, because the mean of its divisors is an integer number (17870872968).

Almost surely, 2^123721428195 is an apocalyptic number.

123721428195 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

123721428195 is a deficient number, since it is larger than the sum of its proper divisors (90729047421).

123721428195 is a wasteful number, since it uses less digits than its factorization.

123721428195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2749365082 (or 2749365079 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The spelling of 123721428195 in words is "one hundred twenty-three billion, seven hundred twenty-one million, four hundred twenty-eight thousand, one hundred ninety-five".