64681206137 has 4 divisors (see below), whose sum is σ = 64682206836. Its totient is φ = 64680205440.

The previous prime is 64681206131. The next prime is 64681206143. The reversal of 64681206137 is 73160218646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73160218646 = 2 ⋅36580109323.

It is an interprime number because it is at equal distance from previous prime (64681206131) and next prime (64681206143).

It can be written as a sum of positive squares in 2 ways, for example, as 43195802896 + 21485403241 = 207836^2 + 146579^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64681206137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64681206131) 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, 396164 + ... + 535077.

It is an arithmetic number, because the mean of its divisors is an integer number (16170551709).

Almost surely, 2^64681206137 is an apocalyptic number.

It is an amenable number.

64681206137 is a deficient number, since it is larger than the sum of its proper divisors (1000699).

64681206137 is an equidigital number, since it uses as much as digits as its factorization.

64681206137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000698.

The product of its (nonzero) digits is 290304, while the sum is 44.

The spelling of 64681206137 in words is "sixty-four billion, six hundred eighty-one million, two hundred six thousand, one hundred thirty-seven".