64891213 has 4 divisors (see below), whose sum is σ = 68306560. Its totient is φ = 61475868.

The previous prime is 64891201. The next prime is 64891217. The reversal of 64891213 is 31219846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 64891213 - 2⁵ = 64891181 is a prime.

It is a super-2 number, since 2×64891213² = 8421739049222738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64891217) 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, 1707645 + ... + 1707682.

It is an arithmetic number, because the mean of its divisors is an integer number (17076640).

Almost surely, 2^64891213 is an apocalyptic number.

It is an amenable number.

64891213 is a deficient number, since it is larger than the sum of its proper divisors (3415347).

64891213 is a wasteful number, since it uses less digits than its factorization.

64891213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3415346.

The product of its digits is 10368, while the sum is 34.

The square root of 64891213 is about 8055.5082397078. The cubic root of 64891213 is about 401.8481415310.

The spelling of 64891213 in words is "sixty-four million, eight hundred ninety-one thousand, two hundred thirteen".