19720650 has 48 divisors (see below), whose sum is σ = 50496768. Its totient is φ = 5088000.

The previous prime is 19720639. The next prime is 19720661. The reversal of 19720650 is 5602791.

It is an interprime number because it is at equal distance from previous prime (19720639) and next prime (19720661).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2530 + ... + 6770.

It is an arithmetic number, because the mean of its divisors is an integer number (1052016).

Almost surely, 2^19720650 is an apocalyptic number.

19720650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19720650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25248384).

19720650 is an abundant number, since it is smaller than the sum of its proper divisors (30776118).

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

19720650 is a wasteful number, since it uses less digits than its factorization.

19720650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4287 (or 4282 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 19720650 is about 4440.7938479511. The cubic root of 19720650 is about 270.1720439854.

The spelling of 19720650 in words is "nineteen million, seven hundred twenty thousand, six hundred fifty".