819814640 has 20 divisors (see below), whose sum is σ = 1906069224. Its totient is φ = 327925824.

The previous prime is 819814577. The next prime is 819814643. The reversal of 819814640 is 46418918.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819814643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5123762 + ... + 5123921.

Almost surely, 2^819814640 is an apocalyptic number.

819814640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

819814640 is an abundant number, since it is smaller than the sum of its proper divisors (1086254584).

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

819814640 is a wasteful number, since it uses less digits than its factorization.

819814640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10247696 (or 10247690 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 819814640 is about 28632.4054176382. The cubic root of 819814640 is about 935.9196305211.

The spelling of 819814640 in words is "eight hundred nineteen million, eight hundred fourteen thousand, six hundred forty".