2161155504225 has 24 divisors (see below), whose sum is σ = 3587936648032. Its totient is φ = 1147833619200.

The previous prime is 2161155504217. The next prime is 2161155504229. The reversal of 2161155504225 is 5224055511612.

It is a happy number.

It is not a de Polignac number, because 2161155504225 - 2³ = 2161155504217 is a prime.

It is a super-2 number, since 2×2161155504225² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2161155504229) 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, 59764927 + ... + 59801076.

Almost surely, 2^{2161155504225} is an apocalyptic number.

2161155504225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2161155504225 is a deficient number, since it is larger than the sum of its proper divisors (1426781143807).

2161155504225 is a wasteful number, since it uses less digits than its factorization.

2161155504225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119566257 (or 119566252 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 39.

The spelling of 2161155504225 in words is "two trillion, one hundred sixty-one billion, one hundred fifty-five million, five hundred four thousand, two hundred twenty-five".