81823437 has 12 divisors (see below), whose sum is σ = 119809404. Its totient is φ = 53801280.

The previous prime is 81823411. The next prime is 81823459. The reversal of 81823437 is 73432818.

It can be written as a sum of positive squares in 2 ways, for example, as 15139881 + 66683556 = 3891^2 + 8166^2 .

It is not a de Polignac number, because 81823437 - 2¹⁰ = 81822413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81823037) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61614 + ... + 62927.

It is an arithmetic number, because the mean of its divisors is an integer number (9984117).

Almost surely, 2^81823437 is an apocalyptic number.

It is an amenable number.

81823437 is a deficient number, since it is larger than the sum of its proper divisors (37985967).

81823437 is a wasteful number, since it uses less digits than its factorization.

81823437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124620 (or 124617 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 81823437 is about 9045.6308237734. The cubic root of 81823437 is about 434.1361055277.

The spelling of 81823437 in words is "eighty-one million, eight hundred twenty-three thousand, four hundred thirty-seven".