81632371 has 2 divisors, whose sum is σ = 81632372. Its totient is φ = 81632370.

The previous prime is 81632363. The next prime is 81632399. The reversal of 81632371 is 17323618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81632371 - 2³ = 81632363 is a prime.

It is not a weakly prime, because it can be changed into another prime (81632671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40816185 + 40816186.

It is an arithmetic number, because the mean of its divisors is an integer number (40816186).

Almost surely, 2^81632371 is an apocalyptic number.

81632371 is a deficient number, since it is larger than the sum of its proper divisors (1).

81632371 is an equidigital number, since it uses as much as digits as its factorization.

81632371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 81632371 is about 9035.0634198106. The cubic root of 81632371 is about 433.7979249258.

Adding to 81632371 its reverse (17323618), we get a palindrome (98955989).

The spelling of 81632371 in words is "eighty-one million, six hundred thirty-two thousand, three hundred seventy-one".