1251040101 has 4 divisors (see below), whose sum is σ = 1668053472. Its totient is φ = 834026732.

The previous prime is 1251040099. The next prime is 1251040103. The reversal of 1251040101 is 1010401521.

It is a happy number.

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: 1010401521 = 3 ⋅336800507.

It is an interprime number because it is at equal distance from previous prime (1251040099) and next prime (1251040103).

It is a cyclic number.

It is not a de Polignac number, because 1251040101 - 2¹ = 1251040099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251040103) 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, 208506681 + ... + 208506686.

It is an arithmetic number, because the mean of its divisors is an integer number (417013368).

Almost surely, 2^1251040101 is an apocalyptic number.

It is an amenable number.

1251040101 is a deficient number, since it is larger than the sum of its proper divisors (417013371).

1251040101 is an equidigital number, since it uses as much as digits as its factorization.

1251040101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417013370.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 1251040101 is about 35370.0452501831. The cubic root of 1251040101 is about 1077.5160394754.

Adding to 1251040101 its reverse (1010401521), we get a palindrome (2261441622).

The spelling of 1251040101 in words is "one billion, two hundred fifty-one million, forty thousand, one hundred one".