661767767097 has 16 divisors (see below), whose sum is σ = 887039083008. Its totient is φ = 438841307520.

The previous prime is 661767767093. The next prime is 661767767131. The reversal of 661767767097 is 790767767166.

It is not a de Polignac number, because 661767767097 - 2² = 661767767093 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661767767093) 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, 215043 + ... + 1170375.

It is an arithmetic number, because the mean of its divisors is an integer number (55439942688).

Almost surely, 2^661767767097 is an apocalyptic number.

It is an amenable number.

661767767097 is a deficient number, since it is larger than the sum of its proper divisors (225271315911).

661767767097 is a wasteful number, since it uses less digits than its factorization.

661767767097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956560.

The product of its (nonzero) digits is 196036848, while the sum is 69.

Adding to 661767767097 its sum of digits (69), we get a palindrome (661767767166).

The spelling of 661767767097 in words is "six hundred sixty-one billion, seven hundred sixty-seven million, seven hundred sixty-seven thousand, ninety-seven".