21512762829 has 12 divisors (see below), whose sum is σ = 32901872796. Its totient is φ = 13498204032.

The previous prime is 21512762827. The next prime is 21512762849. The reversal of 21512762829 is 92826721512.

21512762829 is a `hidden beast` number, since 2 + 1 + 5 + 12 + 7 + 628 + 2 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5825200329 + 15687562500 = 76323^2 + 125250^2 .

It is not a de Polignac number, because 21512762829 - 2¹ = 21512762827 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512762827) 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, 70302994 + ... + 70303299.

It is an arithmetic number, because the mean of its divisors is an integer number (2741822733).

Almost surely, 2^21512762829 is an apocalyptic number.

It is an amenable number.

21512762829 is a deficient number, since it is larger than the sum of its proper divisors (11389109967).

21512762829 is a wasteful number, since it uses less digits than its factorization.

21512762829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140606316 (or 140606313 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The spelling of 21512762829 in words is "twenty-one billion, five hundred twelve million, seven hundred sixty-two thousand, eight hundred twenty-nine".