11894729581 has 32 divisors (see below), whose sum is σ = 14827622400. Its totient is φ = 9310230720.

The previous prime is 11894729569. The next prime is 11894729593. The reversal of 11894729581 is 18592749811.

It is an interprime number because it is at equal distance from previous prime (11894729569) and next prime (11894729593).

It is not a de Polignac number, because 11894729581 - 2⁹ = 11894729069 is a prime.

It is a super-2 number, since 2×11894729581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11894729681) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2662956 + ... + 2667418.

It is an arithmetic number, because the mean of its divisors is an integer number (463363200).

Almost surely, 2^11894729581 is an apocalyptic number.

It is an amenable number.

11894729581 is a deficient number, since it is larger than the sum of its proper divisors (2932892819).

11894729581 is a wasteful number, since it uses less digits than its factorization.

11894729581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5209.

The product of its digits is 1451520, while the sum is 55.

The spelling of 11894729581 in words is "eleven billion, eight hundred ninety-four million, seven hundred twenty-nine thousand, five hundred eighty-one".