81849407 has 8 divisors (see below), whose sum is σ = 88778592. Its totient is φ = 75155200.

The previous prime is 81849401. The next prime is 81849413. The reversal of 81849407 is 70494818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81849401) and next prime (81849413).

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 81849407 - 2⁸ = 81849151 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81849401) 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, 58019 + ... + 59412.

It is an arithmetic number, because the mean of its divisors is an integer number (11097324).

Almost surely, 2^81849407 is an apocalyptic number.

81849407 is a deficient number, since it is larger than the sum of its proper divisors (6929185).

81849407 is a wasteful number, since it uses less digits than its factorization.

81849407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117489.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 81849407 is about 9047.0662095510. The cubic root of 81849407 is about 434.1820309270.

The spelling of 81849407 in words is "eighty-one million, eight hundred forty-nine thousand, four hundred seven".