1021720244 has 12 divisors (see below), whose sum is σ = 1801062564. Its totient is φ = 507130944.

The previous prime is 1021720243. The next prime is 1021720279. The reversal of 1021720244 is 4420271201.

It can be written as a sum of positive squares in 2 ways, for example, as 851939344 + 169780900 = 29188^2 + 13030^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021720241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 931679 + ... + 932774.

It is an arithmetic number, because the mean of its divisors is an integer number (150088547).

Almost surely, 2^1021720244 is an apocalyptic number.

It is an amenable number.

1021720244 is a deficient number, since it is larger than the sum of its proper divisors (779342320).

1021720244 is a wasteful number, since it uses less digits than its factorization.

1021720244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864594 (or 1864592 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 1021720244 is about 31964.3589643215. The cubic root of 1021720244 is about 1007.1882860670.

Adding to 1021720244 its reverse (4420271201), we get a palindrome (5441991445).

The spelling of 1021720244 in words is "one billion, twenty-one million, seven hundred twenty thousand, two hundred forty-four".