81980558 has 16 divisors (see below), whose sum is σ = 134431920. Its totient is φ = 37185600.

The previous prime is 81980543. The next prime is 81980599. The reversal of 81980558 is 85508918.

It is a super-3 number, since 3×81980558³ (a number of 25 digits) contains 333 as substring.

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, 7538 + ... + 14858.

It is an arithmetic number, because the mean of its divisors is an integer number (8401995).

Almost surely, 2^81980558 is an apocalyptic number.

81980558 is a deficient number, since it is larger than the sum of its proper divisors (52451362).

81980558 is a wasteful number, since it uses less digits than its factorization.

81980558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7843.

The product of its (nonzero) digits is 115200, while the sum is 44.

The square root of 81980558 is about 9054.3115696336. The cubic root of 81980558 is about 434.4138103307.

The spelling of 81980558 in words is "eighty-one million, nine hundred eighty thousand, five hundred fifty-eight".