81498778 has 8 divisors (see below), whose sum is σ = 122447520. Its totient is φ = 40682940.

The previous prime is 81498763. The next prime is 81498793. The reversal of 81498778 is 87789418.

It is an interprime number because it is at equal distance from previous prime (81498763) and next prime (81498793).

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31678 + ... + 34153.

It is an arithmetic number, because the mean of its divisors is an integer number (15305940).

Almost surely, 2^81498778 is an apocalyptic number.

81498778 is a deficient number, since it is larger than the sum of its proper divisors (40948742).

81498778 is a wasteful number, since it uses less digits than its factorization.

81498778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66452.

The product of its digits is 903168, while the sum is 52.

The square root of 81498778 is about 9027.6673620598. The cubic root of 81498778 is about 433.5611560735.

The spelling of 81498778 in words is "eighty-one million, four hundred ninety-eight thousand, seven hundred seventy-eight".