64971997 has 2 divisors, whose sum is σ = 64971998. Its totient is φ = 64971996.

The previous prime is 64971967. The next prime is 64972009. The reversal of 64971997 is 79917946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34269316 + 30702681 = 5854^2 + 5541^2 .

It is a cyclic number.

It is not a de Polignac number, because 64971997 - 2¹⁵ = 64939229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64971917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32485998 + 32485999.

It is an arithmetic number, because the mean of its divisors is an integer number (32485999).

Almost surely, 2^64971997 is an apocalyptic number.

It is an amenable number.

64971997 is a deficient number, since it is larger than the sum of its proper divisors (1).

64971997 is an equidigital number, since it uses as much as digits as its factorization.

64971997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 857304, while the sum is 52.

The square root of 64971997 is about 8060.5208888756. The cubic root of 64971997 is about 402.0148278814.

The spelling of 64971997 in words is "sixty-four million, nine hundred seventy-one thousand, nine hundred ninety-seven".