81361470 has 16 divisors (see below), whose sum is σ = 195267600. Its totient is φ = 21696384.

The previous prime is 81361463. The next prime is 81361481. The reversal of 81361470 is 7416318.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 2712049 = 81361470 / (8 + 1 + 3 + 6 + 1 + 4 + 7 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1355995 + ... + 1356054.

It is an arithmetic number, because the mean of its divisors is an integer number (12204225).

Almost surely, 2^81361470 is an apocalyptic number.

81361470 is an abundant number, since it is smaller than the sum of its proper divisors (113906130).

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

81361470 is a wasteful number, since it uses less digits than its factorization.

81361470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712059.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 81361470 is about 9020.0593124436. The cubic root of 81361470 is about 433.3175332832.

Adding to 81361470 its reverse (7416318), we get a palindrome (88777788).

The spelling of 81361470 in words is "eighty-one million, three hundred sixty-one thousand, four hundred seventy".