40001691 has 8 divisors (see below), whose sum is σ = 54636624. Its totient is φ = 26017280.

The previous prime is 40001657. The next prime is 40001711. The reversal of 40001691 is 19610004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40001691 - 2⁶ = 40001627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40001641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162486 + ... + 162731.

It is an arithmetic number, because the mean of its divisors is an integer number (6829578).

Almost surely, 2^40001691 is an apocalyptic number.

40001691 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

40001691 is a deficient number, since it is larger than the sum of its proper divisors (14634933).

40001691 is a wasteful number, since it uses less digits than its factorization.

40001691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325261.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 40001691 is about 6324.6890042120. The cubic root of 40001691 is about 342.0000085496. Note that the first 5 decimals are identical.

Adding to 40001691 its reverse (19610004), we get a palindrome (59611695).

The spelling of 40001691 in words is "forty million, one thousand, six hundred ninety-one".