63857421 has 12 divisors (see below), whose sum is σ = 93979548. Its totient is φ = 41768064.

The previous prime is 63857371. The next prime is 63857429. The reversal of 63857421 is 12475836.

63857421 is a `hidden beast` number, since 63 + 8 + 574 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 43956900 + 19900521 = 6630^2 + 4461^2 .

It is not a de Polignac number, because 63857421 - 2⁹ = 63856909 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63857429) 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, 66460 + ... + 67413.

It is an arithmetic number, because the mean of its divisors is an integer number (7831629).

Almost surely, 2^63857421 is an apocalyptic number.

It is an amenable number.

63857421 is a deficient number, since it is larger than the sum of its proper divisors (30122127).

63857421 is a wasteful number, since it uses less digits than its factorization.

63857421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133932 (or 133929 counting only the distinct ones).

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

The square root of 63857421 is about 7991.0838438850. The cubic root of 63857421 is about 399.7027395620.

The spelling of 63857421 in words is "sixty-three million, eight hundred fifty-seven thousand, four hundred twenty-one".