5031001661 has 4 divisors (see below), whose sum is σ = 5749716192. Its totient is φ = 4312287132.

The previous prime is 5031001643. The next prime is 5031001667. The reversal of 5031001661 is 1661001305.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5031001661 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 (5031001667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359357255 + ... + 359357268.

It is an arithmetic number, because the mean of its divisors is an integer number (1437429048).

Almost surely, 2^5031001661 is an apocalyptic number.

It is an amenable number.

5031001661 is a deficient number, since it is larger than the sum of its proper divisors (718714531).

5031001661 is an equidigital number, since it uses as much as digits as its factorization.

5031001661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718714530.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 5031001661 is about 70929.5542140228. The cubic root of 5031001661 is about 1713.5028070949.

Adding to 5031001661 its reverse (1661001305), we get a palindrome (6692002966).

The spelling of 5031001661 in words is "five billion, thirty-one million, one thousand, six hundred sixty-one".