2155720564 has 24 divisors (see below), whose sum is σ = 3997529928. Its totient is φ = 1013667840.

The previous prime is 2155720507. The next prime is 2155720573. The reversal of 2155720564 is 4650275512.

It can be written as a sum of positive squares in 4 ways, for example, as 6656400 + 2149064164 = 2580^2 + 46358^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80902 + ... + 104194.

It is an arithmetic number, because the mean of its divisors is an integer number (166563747).

Almost surely, 2^2155720564 is an apocalyptic number.

It is an amenable number.

2155720564 is a deficient number, since it is larger than the sum of its proper divisors (1841809364).

2155720564 is a wasteful number, since it uses less digits than its factorization.

2155720564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24675 (or 24673 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 37.

The square root of 2155720564 is about 46429.7379273241. The cubic root of 2155720564 is about 1291.8065676415.

The spelling of 2155720564 in words is "two billion, one hundred fifty-five million, seven hundred twenty thousand, five hundred sixty-four".