81778430 has 32 divisors (see below), whose sum is σ = 151597440. Its totient is φ = 31749120.

The previous prime is 81778423. The next prime is 81778447. The reversal of 81778430 is 3487718.

It is a super-2 number, since 2×81778430² = 13375423226529800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47342 + ... + 49038.

It is an arithmetic number, because the mean of its divisors is an integer number (4737420).

Almost surely, 2^81778430 is an apocalyptic number.

81778430 is a deficient number, since it is larger than the sum of its proper divisors (69819010).

81778430 is a wasteful number, since it uses less digits than its factorization.

81778430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1844.

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 81778430 is about 9043.1427059402. The cubic root of 81778430 is about 434.0564920411.

The spelling of 81778430 in words is "eighty-one million, seven hundred seventy-eight thousand, four hundred thirty".