40193208661 has 4 divisors (see below), whose sum is σ = 40591161324. Its totient is φ = 39795256000.

The previous prime is 40193208659. The next prime is 40193208667. The reversal of 40193208661 is 16680239104.

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

It can be written as a sum of positive squares in 2 ways, for example, as 25017432561 + 15175776100 = 158169^2 + 123190^2 .

It is a cyclic number.

It is not a de Polignac number, because 40193208661 - 2¹ = 40193208659 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 (40193208667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198976180 + ... + 198976381.

It is an arithmetic number, because the mean of its divisors is an integer number (10147790331).

Almost surely, 2^40193208661 is an apocalyptic number.

It is an amenable number.

40193208661 is a deficient number, since it is larger than the sum of its proper divisors (397952663).

40193208661 is a wasteful number, since it uses less digits than its factorization.

40193208661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397952662.

The product of its (nonzero) digits is 62208, while the sum is 40.

The spelling of 40193208661 in words is "forty billion, one hundred ninety-three million, two hundred eight thousand, six hundred sixty-one".