661143001 has 2 divisors, whose sum is σ = 661143002. Its totient is φ = 661143000.

The previous prime is 661142987. The next prime is 661143011. The reversal of 661143001 is 100341166.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 555073600 + 106069401 = 23560^2 + 10299^2 .

It is a cyclic number.

It is not a de Polignac number, because 661143001 - 2¹⁷ = 661011929 is a prime.

It is a super-2 number, since 2×661143001² = 874220135542572002, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661143011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330571500 + 330571501.

It is an arithmetic number, because the mean of its divisors is an integer number (330571501).

Almost surely, 2^661143001 is an apocalyptic number.

It is an amenable number.

661143001 is a deficient number, since it is larger than the sum of its proper divisors (1).

661143001 is an equidigital number, since it uses as much as digits as its factorization.

661143001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 661143001 is about 25712.7011610994. The cubic root of 661143001 is about 871.1610872559.

Adding to 661143001 its reverse (100341166), we get a palindrome (761484167).

The spelling of 661143001 in words is "six hundred sixty-one million, one hundred forty-three thousand, one".