81380351 has 8 divisors (see below), whose sum is σ = 90662880. Its totient is φ = 72529632.

The previous prime is 81380339. The next prime is 81380357. The reversal of 81380351 is 15308318.

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 81380351 - 2¹⁸ = 81118207 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81380357) 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, 107555 + ... + 108308.

It is an arithmetic number, because the mean of its divisors is an integer number (11332860).

Almost surely, 2^81380351 is an apocalyptic number.

81380351 is a deficient number, since it is larger than the sum of its proper divisors (9282529).

81380351 is a wasteful number, since it uses less digits than its factorization.

81380351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215905.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 81380351 is about 9021.1058634737. The cubic root of 81380351 is about 433.3510497030.

Adding to 81380351 its reverse (15308318), we get a palindrome (96688669).

The spelling of 81380351 in words is "eighty-one million, three hundred eighty thousand, three hundred fifty-one".