64721853 has 12 divisors (see below), whose sum is σ = 106842528. Its totient is φ = 36983880.

The previous prime is 64721849. The next prime is 64721869. The reversal of 64721853 is 35812746.

64721853 is a `hidden beast` number, since 6 + 472 + 185 + 3 = 666.

It is not a de Polignac number, because 64721853 - 2² = 64721849 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64721803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 513603 + ... + 513728.

It is an arithmetic number, because the mean of its divisors is an integer number (8903544).

Almost surely, 2^64721853 is an apocalyptic number.

64721853 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

64721853 is a deficient number, since it is larger than the sum of its proper divisors (42120675).

64721853 is a wasteful number, since it uses less digits than its factorization.

64721853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027344 (or 1027341 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 64721853 is about 8044.9893101234. The cubic root of 64721853 is about 401.4982415905.

It can be divided in two parts, 647 and 21853, that added together give a square (22500 = 150²).

The spelling of 64721853 in words is "sixty-four million, seven hundred twenty-one thousand, eight hundred fifty-three".