1021213440 has 288 divisors, whose sum is σ = 3904367040. Its totient is φ = 251265024.

The previous prime is 1021213433. The next prime is 1021213441. The reversal of 1021213440 is 443121201.

1021213440 is a `hidden beast` number, since 1 + 0 + 212 + 13 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021213441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 448144 + ... + 450416.

It is an arithmetic number, because the mean of its divisors is an integer number (13556830).

Almost surely, 2^1021213440 is an apocalyptic number.

1021213440 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 1021213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1952183520).

1021213440 is an abundant number, since it is smaller than the sum of its proper divisors (2883153600).

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

1021213440 is a wasteful number, since it uses less digits than its factorization.

1021213440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2316 (or 2296 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1021213440 is about 31956.4303388223. The cubic root of 1021213440 is about 1007.0217266207.

Adding to 1021213440 its reverse (443121201), we get a palindrome (1464334641).

The spelling of 1021213440 in words is "one billion, twenty-one million, two hundred thirteen thousand, four hundred forty".