661373429 has 2 divisors, whose sum is σ = 661373430. Its totient is φ = 661373428.

The previous prime is 661373399. The next prime is 661373443. The reversal of 661373429 is 924373166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 590392804 + 70980625 = 24298^2 + 8425^2 .

It is a cyclic number.

It is not a de Polignac number, because 661373429 - 2²⁰ = 660324853 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661373029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330686714 + 330686715.

It is an arithmetic number, because the mean of its divisors is an integer number (330686715).

Almost surely, 2^661373429 is an apocalyptic number.

It is an amenable number.

661373429 is a deficient number, since it is larger than the sum of its proper divisors (1).

661373429 is an equidigital number, since it uses as much as digits as its factorization.

661373429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 41.

The square root of 661373429 is about 25717.1815913020. The cubic root of 661373429 is about 871.2622840167.

The spelling of 661373429 in words is "six hundred sixty-one million, three hundred seventy-three thousand, four hundred twenty-nine".