1020202391 has 12 divisors (see below), whose sum is σ = 1124850888. Its totient is φ = 919803024.

The previous prime is 1020202387. The next prime is 1020202399. The reversal of 1020202391 is 1932020201.

It is not a de Polignac number, because 1020202391 - 2² = 1020202387 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 (1020202399) 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, 2816 + ... + 45258.

It is an arithmetic number, because the mean of its divisors is an integer number (93737574).

Almost surely, 2^1020202391 is an apocalyptic number.

1020202391 is a deficient number, since it is larger than the sum of its proper divisors (104648497).

1020202391 is an equidigital number, since it uses as much as digits as its factorization.

1020202391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42542 (or 42499 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1020202391 is about 31940.6072421925. The cubic root of 1020202391 is about 1006.6892840383.

Adding to 1020202391 its reverse (1932020201), we get a palindrome (2952222592).

The spelling of 1020202391 in words is "one billion, twenty million, two hundred two thousand, three hundred ninety-one".