81025534 has 4 divisors (see below), whose sum is σ = 121538304. Its totient is φ = 40512766.

The previous prime is 81025531. The next prime is 81025559. The reversal of 81025534 is 43552018.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81025531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20256382 + ... + 20256385.

It is an arithmetic number, because the mean of its divisors is an integer number (30384576).

Almost surely, 2^81025534 is an apocalyptic number.

81025534 is a deficient number, since it is larger than the sum of its proper divisors (40512770).

81025534 is a wasteful number, since it uses less digits than its factorization.

81025534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40512769.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 81025534 is about 9001.4184437787. The cubic root of 81025534 is about 432.7203310077.

The spelling of 81025534 in words is "eighty-one million, twenty-five thousand, five hundred thirty-four".