81523552 has 72 divisors (see below), whose sum is σ = 181671336. Its totient is φ = 35712000.

The previous prime is 81523537. The next prime is 81523567. The reversal of 81523552 is 25532518.

It is an interprime number because it is at equal distance from previous prime (81523537) and next prime (81523567).

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 338152 + ... + 338392.

It is an arithmetic number, because the mean of its divisors is an integer number (2523213).

Almost surely, 2^81523552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81523552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90835668).

81523552 is an abundant number, since it is smaller than the sum of its proper divisors (100147784).

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

81523552 is a wasteful number, since it uses less digits than its factorization.

81523552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324 (or 285 counting only the distinct ones).

The product of its digits is 12000, while the sum is 31.

The square root of 81523552 is about 9029.0393730452. The cubic root of 81523552 is about 433.6050829322.

The spelling of 81523552 in words is "eighty-one million, five hundred twenty-three thousand, five hundred fifty-two".