81277020 has 120 divisors (see below), whose sum is σ = 278209008. Its totient is φ = 19699200.

The previous prime is 81277019. The next prime is 81277039. The reversal of 81277020 is 2077218.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 15540 + ... + 20100.

Almost surely, 2^81277020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81277020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139104504).

81277020 is an abundant number, since it is smaller than the sum of its proper divisors (196931988).

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

81277020 is a wasteful number, since it uses less digits than its factorization.

81277020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4593 (or 4582 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 81277020 is about 9015.3768640030. The cubic root of 81277020 is about 433.1675592070.

The spelling of 81277020 in words is "eighty-one million, two hundred seventy-seven thousand, twenty".