81023700 has 72 divisors (see below), whose sum is σ = 248234112. Its totient is φ = 20334080.

The previous prime is 81023693. The next prime is 81023707. The reversal of 81023700 is 732018.

It is an interprime number because it is at equal distance from previous prime (81023693) and next prime (81023707).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81023707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2844 + ... + 13043.

It is an arithmetic number, because the mean of its divisors is an integer number (3447696).

Almost surely, 2^81023700 is an apocalyptic number.

It is an amenable number.

81023700 is an abundant number, since it is smaller than the sum of its proper divisors (167210412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81023700 is a wasteful number, since it uses less digits than its factorization.

81023700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15921 (or 15914 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 81023700 is about 9001.3165703690. The cubic root of 81023700 is about 432.7170661313.

Adding to 81023700 its reverse (732018), we get a palindrome (81755718).

The spelling of 81023700 in words is "eighty-one million, twenty-three thousand, seven hundred".