2155540999 has 2 divisors, whose sum is σ = 2155541000. Its totient is φ = 2155540998.

The previous prime is 2155540973. The next prime is 2155541033. The reversal of 2155540999 is 9990455512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2155540999 - 2⁵ = 2155540967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2155540399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077770499 + 1077770500.

It is an arithmetic number, because the mean of its divisors is an integer number (1077770500).

Almost surely, 2^2155540999 is an apocalyptic number.

2155540999 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155540999 is an equidigital number, since it uses as much as digits as its factorization.

2155540999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729000, while the sum is 49.

The square root of 2155540999 is about 46427.8041587151. The cubic root of 2155540999 is about 1291.7706987861.

The spelling of 2155540999 in words is "two billion, one hundred fifty-five million, five hundred forty thousand, nine hundred ninety-nine".