81700245 has 48 divisors (see below), whose sum is σ = 160235712. Its totient is φ = 39605760.

The previous prime is 81700237. The next prime is 81700253. The reversal of 81700245 is 54200718.

It is an interprime number because it is at equal distance from previous prime (81700237) and next prime (81700253).

It is not a de Polignac number, because 81700245 - 2³ = 81700237 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10309 + ... + 16421.

It is an arithmetic number, because the mean of its divisors is an integer number (3338244).

Almost surely, 2^81700245 is an apocalyptic number.

It is an amenable number.

81700245 is a deficient number, since it is larger than the sum of its proper divisors (78535467).

81700245 is a wasteful number, since it uses less digits than its factorization.

81700245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6144 (or 6132 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 81700245 is about 9038.8187834473. The cubic root of 81700245 is about 433.9181200697.

The spelling of 81700245 in words is "eighty-one million, seven hundred thousand, two hundred forty-five".