91009402 has 16 divisors (see below), whose sum is σ = 149094432. Its totient is φ = 41320720.

The previous prime is 91009393. The next prime is 91009403. The reversal of 91009402 is 20490019.

It is a super-2 number, since 2×91009402² = 16565422504795208, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91009403) 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, 23808 + ... + 27364.

It is an arithmetic number, because the mean of its divisors is an integer number (9318402).

Almost surely, 2^91009402 is an apocalyptic number.

91009402 is a deficient number, since it is larger than the sum of its proper divisors (58085030).

91009402 is a wasteful number, since it uses less digits than its factorization.

91009402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4733.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 91009402 is about 9539.8848001430. The cubic root of 91009402 is about 449.8096347067.

The spelling of 91009402 in words is "ninety-one million, nine thousand, four hundred two".