1251441521 has 4 divisors (see below), whose sum is σ = 1365208944. Its totient is φ = 1137674100.

The previous prime is 1251441509. The next prime is 1251441533.

It is a happy number.

1251441521 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1251441509) and next prime (1251441533).

It is a cyclic number.

It is not a de Polignac number, because 1251441521 - 2²⁶ = 1184332657 is a prime.

It is a super-2 number, since 2×1251441521² = 3132211760965586882, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1251441551) 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, 56883695 + ... + 56883716.

It is an arithmetic number, because the mean of its divisors is an integer number (341302236).

Almost surely, 2^1251441521 is an apocalyptic number.

1251441521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1251441521 is a deficient number, since it is larger than the sum of its proper divisors (113767423).

1251441521 is a wasteful number, since it uses less digits than its factorization.

1251441521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113767422.

The product of its digits is 1600, while the sum is 26.

The square root of 1251441521 is about 35375.7193707775. The cubic root of 1251441521 is about 1077.6312743198.

The spelling of 1251441521 in words is "one billion, two hundred fifty-one million, four hundred forty-one thousand, five hundred twenty-one".