91007638 has 16 divisors (see below), whose sum is σ = 137733120. Its totient is φ = 45098856.

The previous prime is 91007633. The next prime is 91007639. The reversal of 91007638 is 83670019.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91007633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186631 + ... + 187117.

It is an arithmetic number, because the mean of its divisors is an integer number (8608320).

Almost surely, 2^91007638 is an apocalyptic number.

91007638 is a deficient number, since it is larger than the sum of its proper divisors (46725482).

91007638 is a wasteful number, since it uses less digits than its factorization.

91007638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 91007638 is about 9539.7923457484. The cubic root of 91007638 is about 449.8067285259.

The spelling of 91007638 in words is "ninety-one million, seven thousand, six hundred thirty-eight".