2172535861 has 2 divisors, whose sum is σ = 2172535862. Its totient is φ = 2172535860.

The previous prime is 2172535793. The next prime is 2172535877. The reversal of 2172535861 is 1685352712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1115960836 + 1056575025 = 33406^2 + 32505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2172535861 is a prime.

It is a super-2 number, since 2×2172535861² = 9439824134662022642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2172535891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086267930 + 1086267931.

It is an arithmetic number, because the mean of its divisors is an integer number (1086267931).

Almost surely, 2^2172535861 is an apocalyptic number.

It is an amenable number.

2172535861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2172535861 is an equidigital number, since it uses as much as digits as its factorization.

2172535861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 40.

The square root of 2172535861 is about 46610.4694355249. The cubic root of 2172535861 is about 1295.1567042024.

The spelling of 2172535861 in words is "two billion, one hundred seventy-two million, five hundred thirty-five thousand, eight hundred sixty-one".