21019392 has 72 divisors (see below), whose sum is σ = 62178480. Its totient is φ = 7004160.

The previous prime is 21019381. The next prime is 21019393. The reversal of 21019392 is 29391012.

21019392 is nontrivially palindromic in base 14.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is not an unprimeable number, because it can be changed into a prime (21019393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5392 + ... + 8432.

It is an arithmetic number, because the mean of its divisors is an integer number (863590).

Almost surely, 2^21019392 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 21019392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31089240).

21019392 is an abundant number, since it is smaller than the sum of its proper divisors (41159088).

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

21019392 is an equidigital number, since it uses as much as digits as its factorization.

21019392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066 (or 3046 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 21019392 is about 4584.6910473880. The cubic root of 21019392 is about 275.9773138253.

The spelling of 21019392 in words is "twenty-one million, nineteen thousand, three hundred ninety-two".