81277939 has 8 divisors (see below), whose sum is σ = 84008960. Its totient is φ = 78553800.

The previous prime is 81277927. The next prime is 81277979. The reversal of 81277939 is 93977218.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81277939 - 2¹⁷ = 81146867 is a prime.

It is a super-2 number, since 2×81277939² = 13212206736175442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81277979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35182 + ... + 37420.

It is an arithmetic number, because the mean of its divisors is an integer number (10501120).

Almost surely, 2^81277939 is an apocalyptic number.

81277939 is a deficient number, since it is larger than the sum of its proper divisors (2731021).

81277939 is a wasteful number, since it uses less digits than its factorization.

81277939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3441.

The product of its digits is 190512, while the sum is 46.

The square root of 81277939 is about 9015.4278323328. The cubic root of 81277939 is about 433.1691918106.

The spelling of 81277939 in words is "eighty-one million, two hundred seventy-seven thousand, nine hundred thirty-nine".