661204593911519 has 4 divisors (see below), whose sum is σ = 755662393041744. Its totient is φ = 566746794781296.

The previous prime is 661204593911473. The next prime is 661204593911531. The reversal of 661204593911519 is 915119395402166.

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

It is a cyclic number.

It is not a de Polignac number, because 661204593911519 - 2⁸ = 661204593911263 is a prime.

It is a super-2 number, since 2×661204593911519² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661204593911539) 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, 47228899565102 + ... + 47228899565115.

It is an arithmetic number, because the mean of its divisors is an integer number (188915598260436).

Almost surely, 2^{661204593911519} is an apocalyptic number.

661204593911519 is a deficient number, since it is larger than the sum of its proper divisors (94457799130225).

661204593911519 is an equidigital number, since it uses as much as digits as its factorization.

661204593911519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94457799130224.

The product of its (nonzero) digits is 15746400, while the sum is 62.

The spelling of 661204593911519 in words is "six hundred sixty-one trillion, two hundred four billion, five hundred ninety-three million, nine hundred eleven thousand, five hundred nineteen".