661235743 has 16 divisors (see below), whose sum is σ = 775916800. Its totient is φ = 563248728.

The previous prime is 661235737. The next prime is 661235749. The reversal of 661235743 is 347532166.

It is an interprime number because it is at equal distance from previous prime (661235737) and next prime (661235749).

It is not a de Polignac number, because 661235743 - 2²⁹ = 124364831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661235749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49996 + ... + 61822.

It is an arithmetic number, because the mean of its divisors is an integer number (48494800).

Almost surely, 2^661235743 is an apocalyptic number.

661235743 is a deficient number, since it is larger than the sum of its proper divisors (114681057).

661235743 is a wasteful number, since it uses less digits than its factorization.

661235743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12011 (or 11997 counting only the distinct ones).

The product of its digits is 90720, while the sum is 37.

The square root of 661235743 is about 25714.5045256563. The cubic root of 661235743 is about 871.2018194646.

The spelling of 661235743 in words is "six hundred sixty-one million, two hundred thirty-five thousand, seven hundred forty-three".