64937881 has 6 divisors (see below), whose sum is σ = 65427882. Its totient is φ = 64451520.

The previous prime is 64937861. The next prime is 64937893. The reversal of 64937881 is 18873946.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 60590656 + 4347225 = 7784^2 + 2085^2 .

It is not a de Polignac number, because 64937881 - 2¹⁷ = 64806809 is a prime.

It is a super-2 number, since 2×64937881² = 8433856777540322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64937861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17641 + ... + 21001.

It is an arithmetic number, because the mean of its divisors is an integer number (10904647).

Almost surely, 2^64937881 is an apocalyptic number.

It is an amenable number.

64937881 is a deficient number, since it is larger than the sum of its proper divisors (490001).

64937881 is an equidigital number, since it uses as much as digits as its factorization.

64937881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3639 (or 3500 counting only the distinct ones).

The product of its digits is 290304, while the sum is 46.

The square root of 64937881 is about 8058.4043705935. The cubic root of 64937881 is about 401.9444512076.

The spelling of 64937881 in words is "sixty-four million, nine hundred thirty-seven thousand, eight hundred eighty-one".