665126051987 has 16 divisors (see below), whose sum is σ = 690667452000. Its totient is φ = 639761869824.

The previous prime is 665126051983. The next prime is 665126051999. The reversal of 665126051987 is 789150621566.

It is a cyclic number.

It is not a de Polignac number, because 665126051987 - 2² = 665126051983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665126051981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10912964 + ... + 10973742.

It is an arithmetic number, because the mean of its divisors is an integer number (43166715750).

Almost surely, 2^665126051987 is an apocalyptic number.

665126051987 is a deficient number, since it is larger than the sum of its proper divisors (25541400013).

665126051987 is a wasteful number, since it uses less digits than its factorization.

665126051987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62230.

The product of its (nonzero) digits is 5443200, while the sum is 56.

The spelling of 665126051987 in words is "six hundred sixty-five billion, one hundred twenty-six million, fifty-one thousand, nine hundred eighty-seven".