20670819840 has 640 divisors, whose sum is σ = 82777559040. Its totient is φ = 4843929600.

The previous prime is 20670819823. The next prime is 20670819887. The reversal of 20670819840 is 4891807602.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23569482 + ... + 23570358.

It is an arithmetic number, because the mean of its divisors is an integer number (129339936).

Almost surely, 2^20670819840 is an apocalyptic number.

20670819840 is a gapful number since it is divisible by the number (20) 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 20670819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41388779520).

20670819840 is an abundant number, since it is smaller than the sum of its proper divisors (62106739200).

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

20670819840 is a wasteful number, since it uses less digits than its factorization.

20670819840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 20670819840 in words is "twenty billion, six hundred seventy million, eight hundred nineteen thousand, eight hundred forty".