661101439 has 2 divisors, whose sum is σ = 661101440. Its totient is φ = 661101438.

The previous prime is 661101401. The next prime is 661101461. The reversal of 661101439 is 934101166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661101439 - 2⁹ = 661100927 is a prime.

It is a super-2 number, since 2×661101439² = 874110225295741442, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661101439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661101499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330550719 + 330550720.

It is an arithmetic number, because the mean of its divisors is an integer number (330550720).

Almost surely, 2^661101439 is an apocalyptic number.

661101439 is a deficient number, since it is larger than the sum of its proper divisors (1).

661101439 is an equidigital number, since it uses as much as digits as its factorization.

661101439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 661101439 is about 25711.8929485948. The cubic root of 661101439 is about 871.1428320243.

The spelling of 661101439 in words is "six hundred sixty-one million, one hundred one thousand, four hundred thirty-nine".