64840427 has 4 divisors (see below), whose sum is σ = 67659600. Its totient is φ = 62021256.

The previous prime is 64840421. The next prime is 64840439. The reversal of 64840427 is 72404846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72404846 = 2 ⋅36202423.

It is a cyclic number.

It is not a de Polignac number, because 64840427 - 2⁴ = 64840411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64840421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1409552 + ... + 1409597.

It is an arithmetic number, because the mean of its divisors is an integer number (16914900).

Almost surely, 2^64840427 is an apocalyptic number.

64840427 is a deficient number, since it is larger than the sum of its proper divisors (2819173).

64840427 is a wasteful number, since it uses less digits than its factorization.

64840427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2819172.

The product of its (nonzero) digits is 43008, while the sum is 35.

The square root of 64840427 is about 8052.3553697039. The cubic root of 64840427 is about 401.7432809747.

The spelling of 64840427 in words is "sixty-four million, eight hundred forty thousand, four hundred twenty-seven".