21190390452 has 960 divisors, whose sum is σ = 81314150400. Its totient is φ = 4694215680.

The previous prime is 21190390439. The next prime is 21190390453. The reversal of 21190390452 is 25409309112.

21190390452 is a `hidden beast` number, since 2 + 119 + 0 + 3 + 90 + 452 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21190390453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 921321313 + ... + 921321335.

It is an arithmetic number, because the mean of its divisors is an integer number (84702240).

Almost surely, 2^21190390452 is an apocalyptic number.

21190390452 is a gapful number since it is divisible by the number (22) 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 21190390452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40657075200).

21190390452 is an abundant number, since it is smaller than the sum of its proper divisors (60123759948).

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

21190390452 is a wasteful number, since it uses less digits than its factorization.

21190390452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

Adding to 21190390452 its reverse (25409309112), we get a palindrome (46599699564).

The spelling of 21190390452 in words is "twenty-one billion, one hundred ninety million, three hundred ninety thousand, four hundred fifty-two".