81698299 has 4 divisors (see below), whose sum is σ = 84333760. Its totient is φ = 79062840.

The previous prime is 81698293. The next prime is 81698327. The reversal of 81698299 is 99289618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81698299 - 2⁷ = 81698171 is a prime.

It is a super-2 number, since 2×81698299² = 13349224118986802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81698293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1317684 + ... + 1317745.

It is an arithmetic number, because the mean of its divisors is an integer number (21083440).

Almost surely, 2^81698299 is an apocalyptic number.

81698299 is a deficient number, since it is larger than the sum of its proper divisors (2635461).

81698299 is a wasteful number, since it uses less digits than its factorization.

81698299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2635460.

The product of its digits is 559872, while the sum is 52.

The square root of 81698299 is about 9038.7111359972. The cubic root of 81698299 is about 433.9146749092.

The spelling of 81698299 in words is "eighty-one million, six hundred ninety-eight thousand, two hundred ninety-nine".