21019017129 has 16 divisors (see below), whose sum is σ = 30706633920. Its totient is φ = 12683165760.

The previous prime is 21019017127. The next prime is 21019017143. The reversal of 21019017129 is 92171091012.

It is not a de Polignac number, because 21019017129 - 2¹ = 21019017127 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 21019017129.

It is not an unprimeable number, because it can be changed into a prime (21019017127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1383142 + ... + 1398255.

It is an arithmetic number, because the mean of its divisors is an integer number (1919164620).

Almost surely, 2^21019017129 is an apocalyptic number.

It is an amenable number.

21019017129 is a deficient number, since it is larger than the sum of its proper divisors (9687616791).

21019017129 is a wasteful number, since it uses less digits than its factorization.

21019017129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2781640.

The product of its (nonzero) digits is 2268, while the sum is 33.

The spelling of 21019017129 in words is "twenty-one billion, nineteen million, seventeen thousand, one hundred twenty-nine".