12172155465 has 24 divisors (see below), whose sum is σ = 20688459840. Its totient is φ = 6109942528.

The previous prime is 12172155371. The next prime is 12172155467. The reversal of 12172155465 is 56455127121.

It is not a de Polignac number, because 12172155465 - 2¹¹ = 12172153417 is a prime.

It is a super-2 number, since 2×12172155465² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12172155467) 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, 1399605 + ... + 1408274.

It is an arithmetic number, because the mean of its divisors is an integer number (862019160).

Almost surely, 2^12172155465 is an apocalyptic number.

12172155465 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12172155465 is a deficient number, since it is larger than the sum of its proper divisors (8516304375).

12172155465 is a wasteful number, since it uses less digits than its factorization.

12172155465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2807921 (or 2807904 counting only the distinct ones).

The product of its digits is 84000, while the sum is 39.

The spelling of 12172155465 in words is "twelve billion, one hundred seventy-two million, one hundred fifty-five thousand, four hundred sixty-five".