20187720 has 96 divisors (see below), whose sum is σ = 74992320. Its totient is φ = 4613760.

The previous prime is 20187719. The next prime is 20187757. The reversal of 20187720 is 2778102.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1486 + ... + 6525.

It is an arithmetic number, because the mean of its divisors is an integer number (781170).

Almost surely, 2^20187720 is an apocalyptic number.

20187720 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 20187720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37496160).

20187720 is an abundant number, since it is smaller than the sum of its proper divisors (54804600).

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

20187720 is a wasteful number, since it uses less digits than its factorization.

20187720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8035 (or 8028 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 20187720 is about 4493.0746710911. The cubic root of 20187720 is about 272.2883691973.

The spelling of 20187720 in words is "twenty million, one hundred eighty-seven thousand, seven hundred twenty".