64021861 has 2 divisors, whose sum is σ = 64021862. Its totient is φ = 64021860.

The previous prime is 64021829. The next prime is 64021901. The reversal of 64021861 is 16812046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55577025 + 8444836 = 7455^2 + 2906^2 .

It is a cyclic number.

It is not a de Polignac number, because 64021861 - 2⁵ = 64021829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64021361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32010930 + 32010931.

It is an arithmetic number, because the mean of its divisors is an integer number (32010931).

Almost surely, 2^64021861 is an apocalyptic number.

It is an amenable number.

64021861 is a deficient number, since it is larger than the sum of its proper divisors (1).

64021861 is an equidigital number, since it uses as much as digits as its factorization.

64021861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 64021861 is about 8001.3661958443. The cubic root of 64021861 is about 400.0455385654.

The spelling of 64021861 in words is "sixty-four million, twenty-one thousand, eight hundred sixty-one".