81423135 has 12 divisors (see below), whose sum is σ = 141133512. Its totient is φ = 43425648.

The previous prime is 81423131. The next prime is 81423137. The reversal of 81423135 is 53132418.

It is a happy number.

It is not a de Polignac number, because 81423135 - 2² = 81423131 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81423099 and 81423108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81423131) 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, 904657 + ... + 904746.

It is an arithmetic number, because the mean of its divisors is an integer number (11761126).

Almost surely, 2^81423135 is an apocalyptic number.

81423135 is a deficient number, since it is larger than the sum of its proper divisors (59710377).

81423135 is a wasteful number, since it uses less digits than its factorization.

81423135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1809414 (or 1809411 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 81423135 is about 9023.4768797842. The cubic root of 81423135 is about 433.4269781179.

The spelling of 81423135 in words is "eighty-one million, four hundred twenty-three thousand, one hundred thirty-five".