2116561640 has 32 divisors (see below), whose sum is σ = 4772635560. Its totient is φ = 844780800.

The previous prime is 2116561633. The next prime is 2116561663. The reversal of 2116561640 is 461656112.

It can be written as a sum of positive squares in 4 ways, for example, as 766293124 + 1350268516 = 27682^2 + 36746^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2116561597 and 2116561606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38951 + ... + 75830.

Almost surely, 2^2116561640 is an apocalyptic number.

2116561640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2116561640 is an abundant number, since it is smaller than the sum of its proper divisors (2656073920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2116561640 is a wasteful number, since it uses less digits than its factorization.

2116561640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115253 (or 115249 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 2116561640 is about 46006.1043775715. The cubic root of 2116561640 is about 1283.9367809507.

The spelling of 2116561640 in words is "two billion, one hundred sixteen million, five hundred sixty-one thousand, six hundred forty".