21305625433 has 6 divisors (see below), whose sum is σ = 22485992874. Its totient is φ = 20184276384.

The previous prime is 21305625421. The next prime is 21305625457. The reversal of 21305625433 is 33452650312.

It can be written as a sum of positive squares in only one way, i.e., 17247043584 + 4058581849 = 131328^2 + 63707^2 .

It is not a de Polignac number, because 21305625433 - 2¹⁷ = 21305494361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21305625463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 29508816 + ... + 29509537.

It is an arithmetic number, because the mean of its divisors is an integer number (3747665479).

Almost surely, 2^21305625433 is an apocalyptic number.

It is an amenable number.

21305625433 is a deficient number, since it is larger than the sum of its proper divisors (1180367441).

21305625433 is an equidigital number, since it uses as much as digits as its factorization.

21305625433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59018391 (or 59018372 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 34.

The spelling of 21305625433 in words is "twenty-one billion, three hundred five million, six hundred twenty-five thousand, four hundred thirty-three".