1020065643 has 28 divisors (see below), whose sum is σ = 1532053728. Its totient is φ = 678864240.

The previous prime is 1020065621. The next prime is 1020065647. The reversal of 1020065643 is 3465600201.

1020065643 is a `hidden beast` number, since 1 + 0 + 2 + 0 + 0 + 656 + 4 + 3 = 666.

It is not a de Polignac number, because 1020065643 - 2⁵ = 1020065611 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1020065647) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 685246 + ... + 686732.

Almost surely, 2^1020065643 is an apocalyptic number.

1020065643 is a deficient number, since it is larger than the sum of its proper divisors (511988085).

1020065643 is an frugal number, since it uses more digits than its factorization.

1020065643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2446 (or 2431 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 1020065643 is about 31938.4665098373. The cubic root of 1020065643 is about 1006.6443031278.

Adding to 1020065643 its reverse (3465600201), we get a palindrome (4485665844).

The spelling of 1020065643 in words is "one billion, twenty million, sixty-five thousand, six hundred forty-three".