1001251663 has 4 divisors (see below), whose sum is σ = 1044784368. Its totient is φ = 957718960.

The previous prime is 1001251649. The next prime is 1001251681. The reversal of 1001251663 is 3661521001.

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 1001251663 - 2¹³ = 1001243471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001251633) 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, 21766318 + ... + 21766363.

It is an arithmetic number, because the mean of its divisors is an integer number (261196092).

Almost surely, 2^1001251663 is an apocalyptic number.

1001251663 is a deficient number, since it is larger than the sum of its proper divisors (43532705).

1001251663 is an equidigital number, since it uses as much as digits as its factorization.

1001251663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43532704.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 1001251663 is about 31642.5609425027. The cubic root of 1001251663 is about 1000.4170470476.

Adding to 1001251663 its reverse (3661521001), we get a palindrome (4662772664).

The spelling of 1001251663 in words is "one billion, one million, two hundred fifty-one thousand, six hundred sixty-three".