64267691 has 4 divisors (see below), whose sum is σ = 64543752. Its totient is φ = 63991632.

The previous prime is 64267669. The next prime is 64267699. The reversal of 64267691 is 19676246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19676246 = 2 ⋅9838123.

It is a cyclic number.

It is not a de Polignac number, because 64267691 - 2⁶ = 64267627 is a prime.

It is a super-2 number, since 2×64267691² = 8260672212942962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64267699) 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, 137681 + ... + 138146.

It is an arithmetic number, because the mean of its divisors is an integer number (16135938).

Almost surely, 2^64267691 is an apocalyptic number.

64267691 is a deficient number, since it is larger than the sum of its proper divisors (276061).

64267691 is a wasteful number, since it uses less digits than its factorization.

64267691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276060.

The product of its digits is 108864, while the sum is 41.

The square root of 64267691 is about 8016.7132292480. The cubic root of 64267691 is about 400.5569138409.

The spelling of 64267691 in words is "sixty-four million, two hundred sixty-seven thousand, six hundred ninety-one".