66557401511 has 4 divisors (see below), whose sum is σ = 66558752832. Its totient is φ = 66556050192.

The previous prime is 66557401507. The next prime is 66557401529. The reversal of 66557401511 is 11510475566.

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 66557401511 - 2² = 66557401507 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 (66557401501) 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, 598871 + ... + 701256.

It is an arithmetic number, because the mean of its divisors is an integer number (16639688208).

Almost surely, 2^66557401511 is an apocalyptic number.

66557401511 is a deficient number, since it is larger than the sum of its proper divisors (1351321).

66557401511 is a wasteful number, since it uses less digits than its factorization.

66557401511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1351320.

The product of its (nonzero) digits is 126000, while the sum is 41.

The spelling of 66557401511 in words is "sixty-six billion, five hundred fifty-seven million, four hundred one thousand, five hundred eleven".