12155002661 has 4 divisors (see below), whose sum is σ = 12275349324. Its totient is φ = 12034656000.

The previous prime is 12155002627. The next prime is 12155002693. The reversal of 12155002661 is 16620055121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16620055121 = 29 ⋅573105349.

It can be written as a sum of positive squares in 2 ways, for example, as 11816994436 + 338008225 = 108706^2 + 18385^2 .

It is a cyclic number.

It is not a de Polignac number, because 12155002661 - 2²² = 12150808357 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 (12155002621) 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, 60173180 + ... + 60173381.

It is an arithmetic number, because the mean of its divisors is an integer number (3068837331).

Almost surely, 2^12155002661 is an apocalyptic number.

It is an amenable number.

12155002661 is a deficient number, since it is larger than the sum of its proper divisors (120346663).

12155002661 is a wasteful number, since it uses less digits than its factorization.

12155002661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120346662.

The product of its (nonzero) digits is 3600, while the sum is 29.

Adding to 12155002661 its reverse (16620055121), we get a palindrome (28775057782).

The spelling of 12155002661 in words is "twelve billion, one hundred fifty-five million, two thousand, six hundred sixty-one".