2155121306 has 16 divisors (see below), whose sum is σ = 3502203264. Its totient is φ = 988713264.

The previous prime is 2155121279. The next prime is 2155121317. The reversal of 2155121306 is 6031215512.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a Curzon number.

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, 243830 + ... + 252513.

It is an arithmetic number, because the mean of its divisors is an integer number (218887704).

Almost surely, 2^2155121306 is an apocalyptic number.

2155121306 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2155121306 is a deficient number, since it is larger than the sum of its proper divisors (1347081958).

2155121306 is a wasteful number, since it uses less digits than its factorization.

2155121306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496525.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 2155121306 is about 46423.2840932220. The cubic root of 2155121306 is about 1291.6868555947.

Adding to 2155121306 its reverse (6031215512), we get a palindrome (8186336818).

The spelling of 2155121306 in words is "two billion, one hundred fifty-five million, one hundred twenty-one thousand, three hundred six".