66426491 has 2 divisors, whose sum is σ = 66426492. Its totient is φ = 66426490.

The previous prime is 66426487. The next prime is 66426551. The reversal of 66426491 is 19462466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66426491 - 2² = 66426487 is a prime.

It is not a weakly prime, because it can be changed into another prime (66426431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33213245 + 33213246.

It is an arithmetic number, because the mean of its divisors is an integer number (33213246).

Almost surely, 2^66426491 is an apocalyptic number.

66426491 is a deficient number, since it is larger than the sum of its proper divisors (1).

66426491 is an equidigital number, since it uses as much as digits as its factorization.

66426491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 38.

The square root of 66426491 is about 8150.2448429480. The cubic root of 66426491 is about 404.9926148122.

The spelling of 66426491 in words is "sixty-six million, four hundred twenty-six thousand, four hundred ninety-one".