26307981 has 24 divisors (see below), whose sum is σ = 44254080. Its totient is φ = 14747616.

The previous prime is 26307977. The next prime is 26307991. The reversal of 26307981 is 18970362.

It is not a de Polignac number, because 26307981 - 2² = 26307977 is a prime.

It is a super-2 number, since 2×26307981² = 1384219728592722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26307991) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 601 + ... + 7278.

It is an arithmetic number, because the mean of its divisors is an integer number (1843920).

Almost surely, 2^26307981 is an apocalyptic number.

26307981 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26307981 is a deficient number, since it is larger than the sum of its proper divisors (17946099).

26307981 is a wasteful number, since it uses less digits than its factorization.

26307981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7945 (or 7942 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 26307981 is about 5129.1306280889. The cubic root of 26307981 is about 297.4147523091.

The spelling of 26307981 in words is "twenty-six million, three hundred seven thousand, nine hundred eighty-one".