1251551 has 4 divisors (see below), whose sum is σ = 1430352. Its totient is φ = 1072752.

The previous prime is 1251533. The next prime is 1251571. The reversal of 1251551 is 1551521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1251551 - 2¹⁰ = 1250527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251571) 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, 89390 + ... + 89403.

It is an arithmetic number, because the mean of its divisors is an integer number (357588).

2^1251551 is an apocalyptic number.

1251551 is a deficient number, since it is larger than the sum of its proper divisors (178801).

1251551 is an equidigital number, since it uses as much as digits as its factorization.

1251551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178800.

The product of its digits is 250, while the sum is 20.

The square root of 1251551 is about 1118.7274020064. The cubic root of 1251551 is about 107.7662697963.

The spelling of 1251551 in words is "one million, two hundred fifty-one thousand, five hundred fifty-one".