81829491840 has 1024 divisors, whose sum is σ = 328805568000. Its totient is φ = 19349176320.

The previous prime is 81829491827. The next prime is 81829491853. The reversal of 81829491840 is 4819492818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81829491827) and next prime (81829491853).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 452096550 + ... + 452096730.

Almost surely, 2^81829491840 is an apocalyptic number.

81829491840 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 81829491840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164402784000).

81829491840 is an abundant number, since it is smaller than the sum of its proper divisors (246976076160).

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

81829491840 is a wasteful number, since it uses less digits than its factorization.

81829491840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 81829491840 in words is "eighty-one billion, eight hundred twenty-nine million, four hundred ninety-one thousand, eight hundred forty".