66550257121 has 4 divisors (see below), whose sum is σ = 66551103792. Its totient is φ = 66549410452.

The previous prime is 66550257101. The next prime is 66550257127. The reversal of 66550257121 is 12175205566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66550257121 - 2¹³ = 66550248929 is a prime.

It is a super-2 number, since 2×66550257121² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66550257127) 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, 291811 + ... + 467176.

It is an arithmetic number, because the mean of its divisors is an integer number (16637775948).

Almost surely, 2^66550257121 is an apocalyptic number.

It is an amenable number.

66550257121 is a deficient number, since it is larger than the sum of its proper divisors (846671).

66550257121 is an equidigital number, since it uses as much as digits as its factorization.

66550257121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846670.

The product of its (nonzero) digits is 126000, while the sum is 40.

The spelling of 66550257121 in words is "sixty-six billion, five hundred fifty million, two hundred fifty-seven thousand, one hundred twenty-one".