1020561653 has 4 divisors (see below), whose sum is σ = 1020644268. Its totient is φ = 1020479040.

The previous prime is 1020561637. The next prime is 1020561691. The reversal of 1020561653 is 3561650201.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3561650201 = 1193 ⋅2985457.

It can be written as a sum of positive squares in 2 ways, for example, as 602849809 + 417711844 = 24553^2 + 20438^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020561653 - 2⁴ = 1020561637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020561623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18626 + ... + 48867.

It is an arithmetic number, because the mean of its divisors is an integer number (255161067).

Almost surely, 2^1020561653 is an apocalyptic number.

It is an amenable number.

1020561653 is a deficient number, since it is larger than the sum of its proper divisors (82615).

1020561653 is an equidigital number, since it uses as much as digits as its factorization.

1020561653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82614.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 1020561653 is about 31946.2306540224. The cubic root of 1020561653 is about 1006.8074379667.

The spelling of 1020561653 in words is "one billion, twenty million, five hundred sixty-one thousand, six hundred fifty-three".