81723000 has 64 divisors (see below), whose sum is σ = 254985120. Its totient is φ = 21792000.

The previous prime is 81722969. The next prime is 81723041. The reversal of 81723000 is 32718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10621 + ... + 16620.

Almost surely, 2^81723000 is an apocalyptic number.

It is an amenable number.

81723000 is an abundant number, since it is smaller than the sum of its proper divisors (173262120).

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

81723000 is a wasteful number, since it uses less digits than its factorization.

81723000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27265 (or 27251 counting only the distinct ones).

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

The square root of 81723000 is about 9040.0774332967. The cubic root of 81723000 is about 433.9584010190.

Adding to 81723000 its reverse (32718), we get a palindrome (81755718).

The spelling of 81723000 in words is "eighty-one million, seven hundred twenty-three thousand".