123171129972 has 72 divisors (see below), whose sum is σ = 345221883552. Its totient is φ = 36712699200.

The previous prime is 123171129901. The next prime is 123171129973. The reversal of 123171129972 is 279921171321.

123171129972 is a `hidden beast` number, since 123 + 171 + 1 + 299 + 72 = 666.

It is a super-2 number, since 2×123171129972² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123171129973) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2525338 + ... + 2573649.

Almost surely, 2^123171129972 is an apocalyptic number.

123171129972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

123171129972 is an abundant number, since it is smaller than the sum of its proper divisors (222050753580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123171129972 is a wasteful number, since it uses less digits than its factorization.

123171129972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5099069 (or 5099064 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The spelling of 123171129972 in words is "one hundred twenty-three billion, one hundred seventy-one million, one hundred twenty-nine thousand, nine hundred seventy-two".