64400837 has 2 divisors, whose sum is σ = 64400838. Its totient is φ = 64400836.

The previous prime is 64400821. The next prime is 64400849. The reversal of 64400837 is 73800446.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49547521 + 14853316 = 7039^2 + 3854^2 .

It is a cyclic number.

It is not a de Polignac number, because 64400837 - 2⁴ = 64400821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64400867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32200418 + 32200419.

It is an arithmetic number, because the mean of its divisors is an integer number (32200419).

Almost surely, 2^64400837 is an apocalyptic number.

It is an amenable number.

64400837 is a deficient number, since it is larger than the sum of its proper divisors (1).

64400837 is an equidigital number, since it uses as much as digits as its factorization.

64400837 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 64400837 is about 8025.0132087119. The cubic root of 64400837 is about 400.8333397399.

The spelling of 64400837 in words is "sixty-four million, four hundred thousand, eight hundred thirty-seven".