81554428 has 24 divisors (see below), whose sum is σ = 147843584. Its totient is φ = 39322800.

The previous prime is 81554419. The next prime is 81554489. The reversal of 81554428 is 82445518.

It is a super-2 number, since 2×81554428² = 13302249452814368, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40051 + ... + 42037.

Almost surely, 2^81554428 is an apocalyptic number.

It is an amenable number.

81554428 is a deficient number, since it is larger than the sum of its proper divisors (66289156).

81554428 is a wasteful number, since it uses less digits than its factorization.

81554428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2353 (or 2351 counting only the distinct ones).

The product of its digits is 51200, while the sum is 37.

The square root of 81554428 is about 9030.7490276278. The cubic root of 81554428 is about 433.6598168113.

The spelling of 81554428 in words is "eighty-one million, five hundred fifty-four thousand, four hundred twenty-eight".