21023035040 has 192 divisors, whose sum is σ = 60726081024. Its totient is φ = 6713376768.

The previous prime is 21023035037. The next prime is 21023035063. The reversal of 21023035040 is 4053032012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

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 31 ways as a sum of consecutive naturals, for example, 1841189 + ... + 1852571.

It is an arithmetic number, because the mean of its divisors is an integer number (316281672).

Almost surely, 2^21023035040 is an apocalyptic number.

21023035040 is a gapful number since it is divisible by the number (20) 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 21023035040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30363040512).

21023035040 is an abundant number, since it is smaller than the sum of its proper divisors (39703045984).

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

21023035040 is a wasteful number, since it uses less digits than its factorization.

21023035040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11519 (or 11511 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

Adding to 21023035040 its reverse (4053032012), we get a palindrome (25076067052).

The spelling of 21023035040 in words is "twenty-one billion, twenty-three million, thirty-five thousand, forty".