661392629 has 4 divisors (see below), whose sum is σ = 670452876. Its totient is φ = 652332384.

The previous prime is 661392617. The next prime is 661392637. The reversal of 661392629 is 926293166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 252746404 + 408646225 = 15898^2 + 20215^2 .

It is a cyclic number.

It is not a de Polignac number, because 661392629 - 2⁸ = 661392373 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661392629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661392659) 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, 4530014 + ... + 4530159.

It is an arithmetic number, because the mean of its divisors is an integer number (167613219).

Almost surely, 2^661392629 is an apocalyptic number.

It is an amenable number.

661392629 is a deficient number, since it is larger than the sum of its proper divisors (9060247).

661392629 is an equidigital number, since it uses as much as digits as its factorization.

661392629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9060246.

The product of its digits is 209952, while the sum is 44.

The square root of 661392629 is about 25717.5548798870. The cubic root of 661392629 is about 871.2707149944.

The spelling of 661392629 in words is "six hundred sixty-one million, three hundred ninety-two thousand, six hundred twenty-nine".