660121043 has 2 divisors, whose sum is σ = 660121044. Its totient is φ = 660121042.

The previous prime is 660121039. The next prime is 660121073. The reversal of 660121043 is 340121066.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660121043 - 2² = 660121039 is a prime.

It is a super-2 number, since 2×660121043² = 871519582822815698, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (660121003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330060521 + 330060522.

It is an arithmetic number, because the mean of its divisors is an integer number (330060522).

Almost surely, 2^660121043 is an apocalyptic number.

660121043 is a deficient number, since it is larger than the sum of its proper divisors (1).

660121043 is an equidigital number, since it uses as much as digits as its factorization.

660121043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 660121043 is about 25692.8208455203. The cubic root of 660121043 is about 870.7119916969.

Adding to 660121043 its sum of digits (23), we get a palindrome (660121066).

The spelling of 660121043 in words is "six hundred sixty million, one hundred twenty-one thousand, forty-three".