81372673 has 4 divisors (see below), whose sum is σ = 81393088. Its totient is φ = 81352260.

The previous prime is 81372671. The next prime is 81372677. The reversal of 81372673 is 37627318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81372673 - 2¹ = 81372671 is a prime.

It is a super-2 number, since 2×81372673² = 13243023822329858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81372671) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2061 + ... + 12922.

It is an arithmetic number, because the mean of its divisors is an integer number (20348272).

Almost surely, 2^81372673 is an apocalyptic number.

It is an amenable number.

81372673 is a deficient number, since it is larger than the sum of its proper divisors (20415).

81372673 is a wasteful number, since it uses less digits than its factorization.

81372673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20414.

The product of its digits is 42336, while the sum is 37.

The square root of 81372673 is about 9020.6802958535. The cubic root of 81372673 is about 433.3374208030.

The spelling of 81372673 in words is "eighty-one million, three hundred seventy-two thousand, six hundred seventy-three".