81409152 has 64 divisors (see below), whose sum is σ = 235913760. Its totient is φ = 24668160.

The previous prime is 81409117. The next prime is 81409187. The reversal of 81409152 is 25190418.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81409117) and next prime (81409187).

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5413 + ... + 13860.

Almost surely, 2^81409152 is an apocalyptic number.

It is an amenable number.

81409152 is an abundant number, since it is smaller than the sum of its proper divisors (154504608).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81409152 is a wasteful number, since it uses less digits than its factorization.

81409152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19301 (or 19289 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 81409152 is about 9022.7020343132. The cubic root of 81409152 is about 433.4021655287.

The spelling of 81409152 in words is "eighty-one million, four hundred nine thousand, one hundred fifty-two".