12007421557 has 4 divisors (see below), whose sum is σ = 12017836780. Its totient is φ = 11997006336.

The previous prime is 12007421533. The next prime is 12007421599. The reversal of 12007421557 is 75512470021.

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 7443203076 + 4564218481 = 86274^2 + 67559^2 .

It is a cyclic number.

It is not a de Polignac number, because 12007421557 - 2³¹ = 9859937909 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 (12007421357) 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, 5205882 + ... + 5208187.

It is an arithmetic number, because the mean of its divisors is an integer number (3004459195).

Almost surely, 2^12007421557 is an apocalyptic number.

It is an amenable number.

12007421557 is a deficient number, since it is larger than the sum of its proper divisors (10415223).

12007421557 is a wasteful number, since it uses less digits than its factorization.

12007421557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10415222.

The product of its (nonzero) digits is 19600, while the sum is 34.

Adding to 12007421557 its reverse (75512470021), we get a palindrome (87519891578).

The spelling of 12007421557 in words is "twelve billion, seven million, four hundred twenty-one thousand, five hundred fifty-seven".