81407370 has 32 divisors (see below), whose sum is σ = 213140160. Its totient is φ = 19735040.

The previous prime is 81407357. The next prime is 81407371. The reversal of 81407370 is 7370418.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81407371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123015 + ... + 123674.

It is an arithmetic number, because the mean of its divisors is an integer number (6660630).

Almost surely, 2^81407370 is an apocalyptic number.

81407370 is an abundant number, since it is smaller than the sum of its proper divisors (131732790).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81407370 is a wasteful number, since it uses less digits than its factorization.

81407370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246710.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 81407370 is about 9022.6032828669. The cubic root of 81407370 is about 433.3990031967.

Adding to 81407370 its reverse (7370418), we get a palindrome (88777788).

The spelling of 81407370 in words is "eighty-one million, four hundred seven thousand, three hundred seventy".