661494937702 has 4 divisors (see below), whose sum is σ = 992242406556. Its totient is φ = 330747468850.

The previous prime is 661494937679. The next prime is 661494937903. The reversal of 661494937702 is 207739494166.

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

It is a super-2 number, since 2×661494937702² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 165373734424 + ... + 165373734427.

It is an arithmetic number, because the mean of its divisors is an integer number (248060601639).

Almost surely, 2^661494937702 is an apocalyptic number.

661494937702 is a deficient number, since it is larger than the sum of its proper divisors (330747468854).

661494937702 is a wasteful number, since it uses less digits than its factorization.

661494937702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330747468853.

The product of its (nonzero) digits is 13716864, while the sum is 58.

The spelling of 661494937702 in words is "six hundred sixty-one billion, four hundred ninety-four million, nine hundred thirty-seven thousand, seven hundred two".