21020231043 has 36 divisors (see below), whose sum is σ = 37397351160. Its totient is φ = 11304994176.

The previous prime is 21020231041. The next prime is 21020231081. The reversal of 21020231043 is 34013202012.

It is not a de Polignac number, because 21020231043 - 2¹ = 21020231041 is a prime.

It is a super-2 number, since 2×21020231043² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21020231041) 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 35 ways as a sum of consecutive naturals, for example, 1394413 + ... + 1409406.

It is an arithmetic number, because the mean of its divisors is an integer number (1038815310).

Almost surely, 2^21020231043 is an apocalyptic number.

21020231043 is a deficient number, since it is larger than the sum of its proper divisors (16377120117).

21020231043 is a wasteful number, since it uses less digits than its factorization.

21020231043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2803856 (or 2803846 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21020231043 its reverse (34013202012), we get a palindrome (55033433055).

The spelling of 21020231043 in words is "twenty-one billion, twenty million, two hundred thirty-one thousand, forty-three".