2015551123 has 4 divisors (see below), whose sum is σ = 2016300600. Its totient is φ = 2014801648.

The previous prime is 2015551121. The next prime is 2015551133. The reversal of 2015551123 is 3211555102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2015551123 - 2¹ = 2015551121 is a prime.

It is a super-2 number, since 2×2015551123² = 8124892658853122258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2015551121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 370690 + ... + 376087.

It is an arithmetic number, because the mean of its divisors is an integer number (504075150).

Almost surely, 2^2015551123 is an apocalyptic number.

2015551123 is a deficient number, since it is larger than the sum of its proper divisors (749477).

2015551123 is an equidigital number, since it uses as much as digits as its factorization.

2015551123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749476.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 2015551123 is about 44894.8897203234. The cubic root of 2015551123 is about 1263.1781536912.

The spelling of 2015551123 in words is "two billion, fifteen million, five hundred fifty-one thousand, one hundred twenty-three".