21620196 has 144 divisors (see below), whose sum is σ = 64209600. Its totient is φ = 6314112.

The previous prime is 21620189. The next prime is 21620197. The reversal of 21620196 is 69102612.

21620196 is a `hidden beast` number, since 21 + 620 + 19 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620197) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 366415 + ... + 366473.

It is an arithmetic number, because the mean of its divisors is an integer number (445900).

Almost surely, 2^21620196 is an apocalyptic number.

21620196 is a gapful number since it is divisible by the number (26) 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 21620196, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32104800).

21620196 is an abundant number, since it is smaller than the sum of its proper divisors (42589404).

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

21620196 is a wasteful number, since it uses less digits than its factorization.

21620196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21620196 is about 4649.7522514646. The cubic root of 21620196 is about 278.5821006900.

The spelling of 21620196 in words is "twenty-one million, six hundred twenty thousand, one hundred ninety-six".