21430751828 has 12 divisors (see below), whose sum is σ = 37742694612. Its totient is φ = 10647124800.

The previous prime is 21430751827. The next prime is 21430751843. The reversal of 21430751828 is 82815703412.

It can be written as a sum of positive squares in 2 ways, for example, as 2869959184 + 18560792644 = 53572^2 + 136238^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430751827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17062073 + ... + 17063328.

It is an arithmetic number, because the mean of its divisors is an integer number (3145224551).

Almost surely, 2^21430751828 is an apocalyptic number.

It is an amenable number.

21430751828 is a deficient number, since it is larger than the sum of its proper divisors (16311942784).

21430751828 is a wasteful number, since it uses less digits than its factorization.

21430751828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34125562 (or 34125560 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 41.

The spelling of 21430751828 in words is "twenty-one billion, four hundred thirty million, seven hundred fifty-one thousand, eight hundred twenty-eight".