81154620 has 36 divisors (see below), whose sum is σ = 246169560. Its totient is φ = 21641184.

The previous prime is 81154589. The next prime is 81154637. The reversal of 81154620 is 2645118.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 225250 + ... + 225609.

Almost surely, 2^81154620 is an apocalyptic number.

It is an amenable number.

81154620 is an abundant number, since it is smaller than the sum of its proper divisors (165014940).

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

81154620 is a wasteful number, since it uses less digits than its factorization.

81154620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450874 (or 450869 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81154620 is about 9008.5859045690. The cubic root of 81154620 is about 432.9500055174.

Adding to 81154620 its reverse (2645118), we get a palindrome (83799738).

The spelling of 81154620 in words is "eighty-one million, one hundred fifty-four thousand, six hundred twenty".