7615611661591 has 4 divisors (see below), whose sum is σ = 7689549638992. Its totient is φ = 7541673684192.

The previous prime is 7615611661583. The next prime is 7615611661607. The reversal of 7615611661591 is 1951661165167.

It is a happy number.

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 7615611661591 - 2³ = 7615611661583 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 (7615611661501) 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, 36968988546 + ... + 36968988751.

It is an arithmetic number, because the mean of its divisors is an integer number (1922387409748).

Almost surely, 2^{7615611661591} is an apocalyptic number.

7615611661591 is a deficient number, since it is larger than the sum of its proper divisors (73937977401).

7615611661591 is a wasteful number, since it uses less digits than its factorization.

7615611661591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73937977400.

The product of its digits is 2041200, while the sum is 55.

The spelling of 7615611661591 in words is "seven trillion, six hundred fifteen billion, six hundred eleven million, six hundred sixty-one thousand, five hundred ninety-one".