1255050721 has 4 divisors (see below), whose sum is σ = 1328877252. Its totient is φ = 1181224192.

The previous prime is 1255050707. The next prime is 1255050733. The reversal of 1255050721 is 1270505521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1270505521 = 967 ⋅1313863.

It can be written as a sum of positive squares in 2 ways, for example, as 518199696 + 736851025 = 22764^2 + 27145^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1255050721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1255050721.

It is not an unprimeable number, because it can be changed into a prime (1255050701) 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, 36913240 + ... + 36913273.

It is an arithmetic number, because the mean of its divisors is an integer number (332219313).

Almost surely, 2^1255050721 is an apocalyptic number.

It is an amenable number.

1255050721 is a deficient number, since it is larger than the sum of its proper divisors (73826531).

1255050721 is an equidigital number, since it uses as much as digits as its factorization.

1255050721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73826530.

The product of its (nonzero) digits is 3500, while the sum is 28.

The square root of 1255050721 is about 35426.6950335478. The cubic root of 1255050721 is about 1078.6662550915. Note that the first 3 decimals are identical.

The spelling of 1255050721 in words is "one billion, two hundred fifty-five million, fifty thousand, seven hundred twenty-one".