81951200357 has 8 divisors (see below), whose sum is σ = 88508023800. Its totient is φ = 75430503360.

The previous prime is 81951200291. The next prime is 81951200363. The reversal of 81951200357 is 75300215918.

It can be written as a sum of positive squares in 4 ways, for example, as 34607532961 + 47343667396 = 186031^2 + 217586^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81951200357 - 2¹⁸ = 81950938213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81951206357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9026894 + ... + 9035967.

It is an arithmetic number, because the mean of its divisors is an integer number (11063502975).

Almost surely, 2^81951200357 is an apocalyptic number.

It is an amenable number.

81951200357 is a deficient number, since it is larger than the sum of its proper divisors (6556823443).

81951200357 is a wasteful number, since it uses less digits than its factorization.

81951200357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18063223.

The product of its (nonzero) digits is 75600, while the sum is 41.

The spelling of 81951200357 in words is "eighty-one billion, nine hundred fifty-one million, two hundred thousand, three hundred fifty-seven".