1251603201 has 4 divisors (see below), whose sum is σ = 1668804272. Its totient is φ = 834402132.

The previous prime is 1251603191. The next prime is 1251603203. The reversal of 1251603201 is 1023061521.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1023061521 = 3 ⋅341020507.

It is not a de Polignac number, because 1251603201 - 2¹⁵ = 1251570433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1251603203) 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, 208600531 + ... + 208600536.

It is an arithmetic number, because the mean of its divisors is an integer number (417201068).

Almost surely, 2^1251603201 is an apocalyptic number.

It is an amenable number.

1251603201 is a deficient number, since it is larger than the sum of its proper divisors (417201071).

1251603201 is an equidigital number, since it uses as much as digits as its factorization.

1251603201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417201070.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 1251603201 is about 35378.0044801851. The cubic root of 1251603201 is about 1077.6776805158.

Adding to 1251603201 its reverse (1023061521), we get a palindrome (2274664722).

The spelling of 1251603201 in words is "one billion, two hundred fifty-one million, six hundred three thousand, two hundred one".