81458603520 has 960 divisors, whose sum is σ = 325618444800. Its totient is φ = 17360093184.

The previous prime is 81458603509. The next prime is 81458603543. The reversal of 81458603520 is 2530685418.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 761295307 + ... + 761295413.

It is an arithmetic number, because the mean of its divisors is an integer number (339185880).

Almost surely, 2^81458603520 is an apocalyptic number.

81458603520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81458603520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162809222400).

81458603520 is an abundant number, since it is smaller than the sum of its proper divisors (244159841280).

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

81458603520 is a wasteful number, since it uses less digits than its factorization.

81458603520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 42.

The spelling of 81458603520 in words is "eighty-one billion, four hundred fifty-eight million, six hundred three thousand, five hundred twenty".