81620594 has 16 divisors (see below), whose sum is σ = 137172096. Its totient is φ = 36097200.

The previous prime is 81620569. The next prime is 81620597. The reversal of 81620594 is 49502618.

It is not an unprimeable number, because it can be changed into a prime (81620597) 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, 49322 + ... + 50949.

It is an arithmetic number, because the mean of its divisors is an integer number (8573256).

Almost surely, 2^81620594 is an apocalyptic number.

81620594 is a deficient number, since it is larger than the sum of its proper divisors (55551502).

81620594 is a wasteful number, since it uses less digits than its factorization.

81620594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100321.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 81620594 is about 9034.4116576565. The cubic root of 81620594 is about 433.7770627612. Note that the first 3 decimals are identical.

The spelling of 81620594 in words is "eighty-one million, six hundred twenty thousand, five hundred ninety-four".