21920472 has 192 divisors, whose sum is σ = 74280960. Its totient is φ = 5702400.

The previous prime is 21920467. The next prime is 21920473. The reversal of 21920472 is 27402912.

21920472 is a `hidden beast` number, since 2 + 192 + 0 + 472 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920473) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 359322 + ... + 359382.

It is an arithmetic number, because the mean of its divisors is an integer number (386880).

Almost surely, 2^21920472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21920472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37140480).

21920472 is an abundant number, since it is smaller than the sum of its proper divisors (52360488).

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

21920472 is a wasteful number, since it uses less digits than its factorization.

21920472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21920472 is about 4681.9303711183. The cubic root of 21920472 is about 279.8658881555.

The spelling of 21920472 in words is "twenty-one million, nine hundred twenty thousand, four hundred seventy-two".