66955651 has 4 divisors (see below), whose sum is σ = 76520752. Its totient is φ = 57390552.

The previous prime is 66955643. The next prime is 66955661. The reversal of 66955651 is 15655966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15655966 = 2 ⋅7827983.

It is a cyclic number.

It is not a de Polignac number, because 66955651 - 2³ = 66955643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66955598 and 66955607.

It is not an unprimeable number, because it can be changed into a prime (66955631) 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, 4782540 + ... + 4782553.

It is an arithmetic number, because the mean of its divisors is an integer number (19130188).

Almost surely, 2^66955651 is an apocalyptic number.

66955651 is a deficient number, since it is larger than the sum of its proper divisors (9565101).

66955651 is an equidigital number, since it uses as much as digits as its factorization.

66955651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9565100.

The product of its digits is 243000, while the sum is 43.

The square root of 66955651 is about 8182.6432770835. The cubic root of 66955651 is about 406.0651755398.

The spelling of 66955651 in words is "sixty-six million, nine hundred fifty-five thousand, six hundred fifty-one".