2165267801961 has 24 divisors (see below), whose sum is σ = 3612639330144. Its totient is φ = 1235090367360.

The previous prime is 2165267801933. The next prime is 2165267801971. The reversal of 2165267801961 is 1691087625612.

It is a happy number.

2165267801961 is a `hidden beast` number, since 21 + 6 + 526 + 7 + 8 + 0 + 1 + 96 + 1 = 666.

It is not a de Polignac number, because 2165267801961 - 2⁷ = 2165267801833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2165267801898 and 2165267801907.

It is not an unprimeable number, because it can be changed into a prime (2165267801971) 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, 643274551 + ... + 643277916.

It is an arithmetic number, because the mean of its divisors is an integer number (150526638756).

Almost surely, 2^{2165267801961} is an apocalyptic number.

It is an amenable number.

2165267801961 is a deficient number, since it is larger than the sum of its proper divisors (1447371528183).

2165267801961 is a wasteful number, since it uses less digits than its factorization.

2165267801961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286552501 (or 1286552498 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 2165267801961 in words is "two trillion, one hundred sixty-five billion, two hundred sixty-seven million, eight hundred one thousand, nine hundred sixty-one".