66861954 has 12 divisors (see below), whose sum is σ = 144867606. Its totient is φ = 22287312.

The previous prime is 66861953. The next prime is 66861959. The reversal of 66861954 is 45916866.

It can be written as a sum of positive squares in only one way, i.e., 66830625 + 31329 = 8175^2 + 177^2 .

It is not an unprimeable number, because it can be changed into a prime (66861953) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1857259 + ... + 1857294.

Almost surely, 2^66861954 is an apocalyptic number.

66861954 is an abundant number, since it is smaller than the sum of its proper divisors (78005652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66861954 is a wasteful number, since it uses less digits than its factorization.

66861954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714561 (or 3714558 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 66861954 is about 8176.9159222778. The cubic root of 66861954 is about 405.8756727393.

The spelling of 66861954 in words is "sixty-six million, eight hundred sixty-one thousand, nine hundred fifty-four".