81951458 has 8 divisors (see below), whose sum is σ = 130158252. Its totient is φ = 38565376.

The previous prime is 81951451. The next prime is 81951473. The reversal of 81951458 is 85415918.

It can be written as a sum of positive squares in 2 ways, for example, as 81667369 + 284089 = 9037^2 + 533^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81951451) 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, 1205135 + ... + 1205202.

Almost surely, 2^81951458 is an apocalyptic number.

81951458 is a deficient number, since it is larger than the sum of its proper divisors (48206794).

81951458 is a wasteful number, since it uses less digits than its factorization.

81951458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2410356.

The product of its digits is 57600, while the sum is 41.

The square root of 81951458 is about 9052.7044577850. The cubic root of 81951458 is about 434.3624040859.

The spelling of 81951458 in words is "eighty-one million, nine hundred fifty-one thousand, four hundred fifty-eight".