5635421721 has 16 divisors (see below), whose sum is σ = 8351318400. Its totient is φ = 3755802384.

The previous prime is 5635421719. The next prime is 5635421731. The reversal of 5635421721 is 1271245365.

5635421721 is a `hidden beast` number, since 5 + 635 + 4 + 2 + 17 + 2 + 1 = 666.

It is not a de Polignac number, because 5635421721 - 2¹ = 5635421719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (5635421711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63580 + ... + 123746.

It is an arithmetic number, because the mean of its divisors is an integer number (521957400).

Almost surely, 2^5635421721 is an apocalyptic number.

It is an amenable number.

5635421721 is a deficient number, since it is larger than the sum of its proper divisors (2715896679).

5635421721 is a wasteful number, since it uses less digits than its factorization.

5635421721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63645 (or 63639 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 5635421721 is about 75069.4459883647. The cubic root of 5635421721 is about 1779.5443138750.

The spelling of 5635421721 in words is "five billion, six hundred thirty-five million, four hundred twenty-one thousand, seven hundred twenty-one".