1021209984 has 128 divisors (see below), whose sum is σ = 3078604800. Its totient is φ = 333107712.

The previous prime is 1021209983. The next prime is 1021209997. The reversal of 1021209984 is 4899021201.

It is a tau number, because it is divible by the number of its divisors (128).

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 (1021209983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159289 + ... + 165575.

It is an arithmetic number, because the mean of its divisors is an integer number (24051600).

Almost surely, 2^1021209984 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 1021209984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1539302400).

1021209984 is an abundant number, since it is smaller than the sum of its proper divisors (2057394816).

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

1021209984 is an equidigital number, since it uses as much as digits as its factorization.

1021209984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6357 (or 6339 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1021209984 is about 31956.3762651525. The cubic root of 1021209984 is about 1007.0205906286.

The spelling of 1021209984 in words is "one billion, twenty-one million, two hundred nine thousand, nine hundred eighty-four".