1021219920 has 640 divisors, whose sum is σ = 4435430400. Its totient is φ = 210567168.

The previous prime is 1021219889. The next prime is 1021219921. The reversal of 1021219920 is 299121201.

1021219920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 (1021219921) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7454092 + ... + 7454228.

It is an arithmetic number, because the mean of its divisors is an integer number (6930360).

Almost surely, 2^1021219920 is an apocalyptic number.

1021219920 is a gapful number since it is divisible by the number (10) 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 1021219920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2217715200).

1021219920 is an abundant number, since it is smaller than the sum of its proper divisors (3414210480).

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

1021219920 is a wasteful number, since it uses less digits than its factorization.

1021219920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 1021219920 is about 31956.5317267065. The cubic root of 1021219920 is about 1007.0238565989.

The spelling of 1021219920 in words is "one billion, twenty-one million, two hundred nineteen thousand, nine hundred twenty".