81423130 has 16 divisors (see below), whose sum is σ = 150137064. Its totient is φ = 31774720.

The previous prime is 81423107. The next prime is 81423131. The reversal of 81423130 is 3132418.

It can be written as a sum of positive squares in 4 ways, for example, as 23068809 + 58354321 = 4803^2 + 7639^2 .

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 7 ways as a sum of consecutive naturals, for example, 98887 + ... + 99706.

Almost surely, 2^81423130 is an apocalyptic number.

81423130 is a deficient number, since it is larger than the sum of its proper divisors (68713934).

81423130 is a wasteful number, since it uses less digits than its factorization.

81423130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198641.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 81423130 is about 9023.4766027291. The cubic root of 81423130 is about 433.4269692460.

Adding to 81423130 its reverse (3132418), we get a palindrome (84555548).

The spelling of 81423130 in words is "eighty-one million, four hundred twenty-three thousand, one hundred thirty".