1251390025 has 6 divisors (see below), whose sum is σ = 1551723662. Its totient is φ = 1001112000.

The previous prime is 1251390013. The next prime is 1251390029. The reversal of 1251390025 is 5200931521.

It can be written as a sum of positive squares in 3 ways, for example, as 387735481 + 863654544 = 19691^2 + 29388^2 .

It is not a de Polignac number, because 1251390025 - 2¹⁵ = 1251357257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1251389975 and 1251390002.

It is not an unprimeable number, because it can be changed into a prime (1251390029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25027776 + ... + 25027825.

Almost surely, 2^1251390025 is an apocalyptic number.

It is an amenable number.

1251390025 is a deficient number, since it is larger than the sum of its proper divisors (300333637).

1251390025 is an equidigital number, since it uses as much as digits as its factorization.

1251390025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50055611 (or 50055606 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 1251390025 is about 35374.9915194336. The cubic root of 1251390025 is about 1077.6164928430.

The spelling of 1251390025 in words is "one billion, two hundred fifty-one million, three hundred ninety thousand, twenty-five".