64243947 has 4 divisors (see below), whose sum is σ = 85658600. Its totient is φ = 42829296.

The previous prime is 64243943. The next prime is 64243967. The reversal of 64243947 is 74934246.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 64243947 - 2² = 64243943 is a prime.

It is a super-2 number, since 2×64243947² = 8254569452277618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64243943) 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, 10707322 + ... + 10707327.

It is an arithmetic number, because the mean of its divisors is an integer number (21414650).

Almost surely, 2^64243947 is an apocalyptic number.

64243947 is a deficient number, since it is larger than the sum of its proper divisors (21414653).

64243947 is a wasteful number, since it uses less digits than its factorization.

64243947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21414652.

The product of its digits is 145152, while the sum is 39.

The square root of 64243947 is about 8015.2321862813. The cubic root of 64243947 is about 400.5075785543.

The spelling of 64243947 in words is "sixty-four million, two hundred forty-three thousand, nine hundred forty-seven".