68638531 has 4 divisors (see below), whose sum is σ = 73918432. Its totient is φ = 63358632.

The previous prime is 68638523. The next prime is 68638541. The reversal of 68638531 is 13583686.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 68638531 - 2³ = 68638523 is a prime.

It is a super-2 number, since 2×68638531² = 9422495875675922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68638501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2639931 + ... + 2639956.

It is an arithmetic number, because the mean of its divisors is an integer number (18479608).

Almost surely, 2^68638531 is an apocalyptic number.

68638531 is a deficient number, since it is larger than the sum of its proper divisors (5279901).

68638531 is a wasteful number, since it uses less digits than its factorization.

68638531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5279900.

The product of its digits is 103680, while the sum is 40.

The square root of 68638531 is about 8284.8374154234. The cubic root of 68638531 is about 409.4391120847.

It can be divided in two parts, 68638 and 531, that added together give a square (69169 = 263²).

The spelling of 68638531 in words is "sixty-eight million, six hundred thirty-eight thousand, five hundred thirty-one".