81904351 has 8 divisors (see below), whose sum is σ = 88017840. Its totient is φ = 75934848.

The previous prime is 81904343. The next prime is 81904373. The reversal of 81904351 is 15340918.

81904351 = T₁₅₃₀ + T₁₅₃₁ + ... + T₁₅₉₆.

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 81904351 - 2³ = 81904343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81904301) 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, 34816 + ... + 37093.

It is an arithmetic number, because the mean of its divisors is an integer number (11002230).

Almost surely, 2^81904351 is an apocalyptic number.

81904351 is a deficient number, since it is larger than the sum of its proper divisors (6113489).

81904351 is a wasteful number, since it uses less digits than its factorization.

81904351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71993.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 81904351 is about 9050.1022646156. The cubic root of 81904351 is about 434.2791619974.

The spelling of 81904351 in words is "eighty-one million, nine hundred four thousand, three hundred fifty-one".