2161236365 has 16 divisors (see below), whose sum is σ = 2607528000. Its totient is φ = 1719653760.

The previous prime is 2161236349. The next prime is 2161236421. The reversal of 2161236365 is 5636321612.

It is not a de Polignac number, because 2161236365 - 2⁴ = 2161236349 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 824537 + ... + 827153.

It is an arithmetic number, because the mean of its divisors is an integer number (162970500).

Almost surely, 2^2161236365 is an apocalyptic number.

It is an amenable number.

2161236365 is a deficient number, since it is larger than the sum of its proper divisors (446291635).

2161236365 is a wasteful number, since it uses less digits than its factorization.

2161236365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3452.

The product of its digits is 38880, while the sum is 35.

The square root of 2161236365 is about 46489.0994212622. The cubic root of 2161236365 is about 1292.9074028698.

Adding to 2161236365 its reverse (5636321612), we get a palindrome (7797557977).

The spelling of 2161236365 in words is "two billion, one hundred sixty-one million, two hundred thirty-six thousand, three hundred sixty-five".