64542251 has 4 divisors (see below), whose sum is σ = 68338872. Its totient is φ = 60745632.

The previous prime is 64542227. The next prime is 64542253. The reversal of 64542251 is 15224546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15224546 = 2 ⋅7612273.

It is a cyclic number.

It is not a de Polignac number, because 64542251 - 2⁶ = 64542187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64542253) 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, 1898285 + ... + 1898318.

It is an arithmetic number, because the mean of its divisors is an integer number (17084718).

Almost surely, 2^64542251 is an apocalyptic number.

64542251 is a deficient number, since it is larger than the sum of its proper divisors (3796621).

64542251 is a wasteful number, since it uses less digits than its factorization.

64542251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3796620.

The product of its digits is 9600, while the sum is 29.

The square root of 64542251 is about 8033.8192038407. The cubic root of 64542251 is about 401.1265140204.

Adding to 64542251 its reverse (15224546), we get a palindrome (79766797).

The spelling of 64542251 in words is "sixty-four million, five hundred forty-two thousand, two hundred fifty-one".