81557046 has 24 divisors (see below), whose sum is σ = 177039720. Its totient is φ = 27134496.

The previous prime is 81557027. The next prime is 81557071. The reversal of 81557046 is 64075518.

81557046 is a `hidden beast` number, since 81 + 5 + 570 + 4 + 6 = 666.

It is a super-2 number, since 2×81557046² = 13303103504492232, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81557046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6261 + ... + 14223.

It is an arithmetic number, because the mean of its divisors is an integer number (7376655).

Almost surely, 2^81557046 is an apocalyptic number.

81557046 is an abundant number, since it is smaller than the sum of its proper divisors (95482674).

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

81557046 is a wasteful number, since it uses less digits than its factorization.

81557046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8540 (or 8537 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 81557046 is about 9030.8939756815. The cubic root of 81557046 is about 433.6644571040.

The spelling of 81557046 in words is "eighty-one million, five hundred fifty-seven thousand, forty-six".