68721535 has 16 divisors (see below), whose sum is σ = 84857472. Its totient is φ = 53395200.

The previous prime is 68721533. The next prime is 68721551. The reversal of 68721535 is 53512786.

It is not a de Polignac number, because 68721535 - 2¹ = 68721533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 68721494 and 68721503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68721533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54937 + ... + 56173.

It is an arithmetic number, because the mean of its divisors is an integer number (5303592).

Almost surely, 2^68721535 is an apocalyptic number.

68721535 is a deficient number, since it is larger than the sum of its proper divisors (16135937).

68721535 is a wasteful number, since it uses less digits than its factorization.

68721535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554.

The product of its digits is 50400, while the sum is 37.

The square root of 68721535 is about 8289.8452940932. The cubic root of 68721535 is about 409.6040893623.

It can be divided in two parts, 687 and 21535, that added together give a palindrome (22222).

The spelling of 68721535 in words is "sixty-eight million, seven hundred twenty-one thousand, five hundred thirty-five".