2161987497 has 64 divisors (see below), whose sum is σ = 3420384000. Its totient is φ = 1347300864.

The previous prime is 2161987481. The next prime is 2161987567. The reversal of 2161987497 is 7947891612.

2161987497 is a `hidden beast` number, since 2 + 1 + 61 + 98 + 7 + 497 = 666.

2161987497 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2161987497 - 2⁴ = 2161987481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2161989497) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5285829 + ... + 5286237.

It is an arithmetic number, because the mean of its divisors is an integer number (53443500).

Almost surely, 2^2161987497 is an apocalyptic number.

2161987497 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

2161987497 is a deficient number, since it is larger than the sum of its proper divisors (1258396503).

2161987497 is a wasteful number, since it uses less digits than its factorization.

2161987497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647 (or 641 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 54.

The square root of 2161987497 is about 46497.1773014234. The cubic root of 2161987497 is about 1293.0571677073.

The spelling of 2161987497 in words is "two billion, one hundred sixty-one million, nine hundred eighty-seven thousand, four hundred ninety-seven".