81098757 has 6 divisors (see below), whose sum is σ = 117142662. Its totient is φ = 54065832.

The previous prime is 81098749. The next prime is 81098803. The reversal of 81098757 is 75789018.

It can be written as a sum of positive squares in only one way, i.e., 80299521 + 799236 = 8961^2 + 894^2 .

It is not a de Polignac number, because 81098757 - 2³ = 81098749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81098057) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4505478 + ... + 4505495.

It is an arithmetic number, because the mean of its divisors is an integer number (19523777).

Almost surely, 2^81098757 is an apocalyptic number.

It is an amenable number.

81098757 is a deficient number, since it is larger than the sum of its proper divisors (36043905).

81098757 is a wasteful number, since it uses less digits than its factorization.

81098757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9010979 (or 9010976 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 81098757 is about 9005.4848287030. The cubic root of 81098757 is about 432.8506419496.

The spelling of 81098757 in words is "eighty-one million, ninety-eight thousand, seven hundred fifty-seven".