66121863 has 4 divisors (see below), whose sum is σ = 88162488. Its totient is φ = 44081240.

The previous prime is 66121841. The next prime is 66121871. The reversal of 66121863 is 36812166.

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 66121863 - 2⁹ = 66121351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66121873) 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, 11020308 + ... + 11020313.

It is an arithmetic number, because the mean of its divisors is an integer number (22040622).

Almost surely, 2^66121863 is an apocalyptic number.

66121863 is a deficient number, since it is larger than the sum of its proper divisors (22040625).

66121863 is a wasteful number, since it uses less digits than its factorization.

66121863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22040624.

The product of its digits is 10368, while the sum is 33.

The square root of 66121863 is about 8131.5350949252. The cubic root of 66121863 is about 404.3725752128.

The spelling of 66121863 in words is "sixty-six million, one hundred twenty-one thousand, eight hundred sixty-three".