1255235021 has 4 divisors (see below), whose sum is σ = 1258960092. Its totient is φ = 1251509952.

The previous prime is 1255235011. The next prime is 1255235039. The reversal of 1255235021 is 1205325521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1205325521 = 29 ⋅41562949.

It can be written as a sum of positive squares in 2 ways, for example, as 102292996 + 1152942025 = 10114^2 + 33955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255235021 - 2¹⁸ = 1254972877 is a prime.

It is a super-3 number, since 3×1255235021³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1255235011) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1862030 + ... + 1862703.

It is an arithmetic number, because the mean of its divisors is an integer number (314740023).

Almost surely, 2^1255235021 is an apocalyptic number.

It is an amenable number.

1255235021 is a deficient number, since it is larger than the sum of its proper divisors (3725071).

1255235021 is an equidigital number, since it uses as much as digits as its factorization.

1255235021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3725070.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 1255235021 is about 35429.2960838908. The cubic root of 1255235021 is about 1078.7190520176.

The spelling of 1255235021 in words is "one billion, two hundred fifty-five million, two hundred thirty-five thousand, twenty-one".