1252550021 has 4 divisors (see below), whose sum is σ = 1326229452. Its totient is φ = 1178870592.

The previous prime is 1252550017. The next prime is 1252550029. The reversal of 1252550021 is 1200552521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1200552521 = 7 ⋅171507503.

It can be written as a sum of positive squares in 2 ways, for example, as 923308996 + 329241025 = 30386^2 + 18145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1252550021 - 2² = 1252550017 is a prime.

It is a Duffinian 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 (1252550029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36839690 + ... + 36839723.

It is an arithmetic number, because the mean of its divisors is an integer number (331557363).

Almost surely, 2^1252550021 is an apocalyptic number.

It is an amenable number.

1252550021 is a deficient number, since it is larger than the sum of its proper divisors (73679431).

1252550021 is an equidigital number, since it uses as much as digits as its factorization.

1252550021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73679430.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 1252550021 is about 35391.3834287387. The cubic root of 1252550021 is about 1077.9493612932.

The spelling of 1252550021 in words is "one billion, two hundred fifty-two million, five hundred fifty thousand, twenty-one".