91438761 has 4 divisors (see below), whose sum is σ = 121918352. Its totient is φ = 60959172.

The previous prime is 91438757. The next prime is 91438807. The reversal of 91438761 is 16783419.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 91438761 - 2² = 91438757 is a prime.

It is a super-2 number, since 2×91438761² = 16722094026430242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91438741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15239791 + ... + 15239796.

It is an arithmetic number, because the mean of its divisors is an integer number (30479588).

Almost surely, 2^91438761 is an apocalyptic number.

It is an amenable number.

91438761 is a deficient number, since it is larger than the sum of its proper divisors (30479591).

91438761 is a wasteful number, since it uses less digits than its factorization.

91438761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30479590.

The product of its digits is 36288, while the sum is 39.

The square root of 91438761 is about 9562.3616852742. The cubic root of 91438761 is about 450.5158873646.

The spelling of 91438761 in words is "ninety-one million, four hundred thirty-eight thousand, seven hundred sixty-one".