1021900842 has 24 divisors (see below), whose sum is σ = 2215458180. Its totient is φ = 340427520.

The previous prime is 1021900823. The next prime is 1021900849. The reversal of 1021900842 is 2480091201.

It can be written as a sum of positive squares in 2 ways, for example, as 936910881 + 84989961 = 30609^2 + 9219^2 .

It is not an unprimeable number, because it can be changed into a prime (1021900849) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15034 + ... + 47642.

Almost surely, 2^1021900842 is an apocalyptic number.

1021900842 is an abundant number, since it is smaller than the sum of its proper divisors (1193557338).

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

1021900842 is a wasteful number, since it uses less digits than its factorization.

1021900842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34358 (or 34355 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1021900842 is about 31967.1838296713. The cubic root of 1021900842 is about 1007.2476256873.

The spelling of 1021900842 in words is "one billion, twenty-one million, nine hundred thousand, eight hundred forty-two".