81380470 has 16 divisors (see below), whose sum is σ = 148968720. Its totient is φ = 32000224.

The previous prime is 81380461. The next prime is 81380471. The reversal of 81380470 is 7408318.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81380471) 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, 68377 + ... + 69556.

It is an arithmetic number, because the mean of its divisors is an integer number (9310545).

Almost surely, 2^81380470 is an apocalyptic number.

81380470 is a deficient number, since it is larger than the sum of its proper divisors (67588250).

81380470 is a wasteful number, since it uses less digits than its factorization.

81380470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137999.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81380470 is about 9021.1124591150. The cubic root of 81380470 is about 433.3512609283.

Adding to 81380470 its reverse (7408318), we get a palindrome (88788788).

The spelling of 81380470 in words is "eighty-one million, three hundred eighty thousand, four hundred seventy".