661254742 has 4 divisors (see below), whose sum is σ = 991882116. Its totient is φ = 330627370.

The previous prime is 661254733. The next prime is 661254791. The reversal of 661254742 is 247452166.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165313684 + ... + 165313687.

It is an arithmetic number, because the mean of its divisors is an integer number (247970529).

Almost surely, 2^661254742 is an apocalyptic number.

661254742 is a deficient number, since it is larger than the sum of its proper divisors (330627374).

661254742 is a wasteful number, since it uses less digits than its factorization.

661254742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330627373.

The product of its digits is 80640, while the sum is 37.

The square root of 661254742 is about 25714.8739448592. The cubic root of 661254742 is about 871.2101633395.

The spelling of 661254742 in words is "six hundred sixty-one million, two hundred fifty-four thousand, seven hundred forty-two".