1200400251 has 16 divisors (see below), whose sum is σ = 1622208000. Its totient is φ = 789487200.

The previous prime is 1200400241. The next prime is 1200400301. The reversal of 1200400251 is 1520040021.

It is not a de Polignac number, because 1200400251 - 2¹⁰ = 1200399227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1200400251.

It is not an unprimeable number, because it can be changed into a prime (1200400211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78750 + ... + 92748.

It is an arithmetic number, because the mean of its divisors is an integer number (101388000).

Almost surely, 2^1200400251 is an apocalyptic number.

1200400251 is a deficient number, since it is larger than the sum of its proper divisors (421807749).

1200400251 is a wasteful number, since it uses less digits than its factorization.

1200400251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14386.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 1200400251 is about 34646.7927952935. The cubic root of 1200400251 is about 1062.7767033146.

Adding to 1200400251 its reverse (1520040021), we get a palindrome (2720440272).

The spelling of 1200400251 in words is "one billion, two hundred million, four hundred thousand, two hundred fifty-one".