1255605990 has 16 divisors (see below), whose sum is σ = 3013454448. Its totient is φ = 334828256.

The previous prime is 1255605983. The next prime is 1255605997. The reversal of 1255605990 is 995065521.

It is an interprime number because it is at equal distance from previous prime (1255605983) and next prime (1255605997).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1255605997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20926737 + ... + 20926796.

It is an arithmetic number, because the mean of its divisors is an integer number (188340903).

Almost surely, 2^1255605990 is an apocalyptic number.

1255605990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1255605990 is an abundant number, since it is smaller than the sum of its proper divisors (1757848458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1255605990 is a wasteful number, since it uses less digits than its factorization.

1255605990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41853543.

The product of its (nonzero) digits is 121500, while the sum is 42.

The square root of 1255605990 is about 35434.5310396511. The cubic root of 1255605990 is about 1078.8253088555.

The spelling of 1255605990 in words is "one billion, two hundred fifty-five million, six hundred five thousand, nine hundred ninety".