81494121 has 4 divisors (see below), whose sum is σ = 108658832. Its totient is φ = 54329412.

The previous prime is 81494111. The next prime is 81494123. The reversal of 81494121 is 12149418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81494121 - 2²⁶ = 14385257 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81494123) 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, 13582351 + ... + 13582356.

It is an arithmetic number, because the mean of its divisors is an integer number (27164708).

Almost surely, 2^81494121 is an apocalyptic number.

It is an amenable number.

81494121 is a deficient number, since it is larger than the sum of its proper divisors (27164711).

81494121 is a wasteful number, since it uses less digits than its factorization.

81494121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27164710.

The product of its digits is 2304, while the sum is 30.

The square root of 81494121 is about 9027.4094290666. The cubic root of 81494121 is about 433.5528977380.

The spelling of 81494121 in words is "eighty-one million, four hundred ninety-four thousand, one hundred twenty-one".