21001283438 has 16 divisors (see below), whose sum is σ = 33361146000. Its totient is φ = 9881129856.

The previous prime is 21001283437. The next prime is 21001283461. The reversal of 21001283438 is 83438210012.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001283431) 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 7 ways as a sum of consecutive naturals, for example, 139313 + ... + 247811.

It is an arithmetic number, because the mean of its divisors is an integer number (2085071625).

Almost surely, 2^21001283438 is an apocalyptic number.

21001283438 is a deficient number, since it is larger than the sum of its proper divisors (12359862562).

21001283438 is a wasteful number, since it uses less digits than its factorization.

21001283438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114211.

The product of its (nonzero) digits is 9216, while the sum is 32.

The spelling of 21001283438 in words is "twenty-one billion, one million, two hundred eighty-three thousand, four hundred thirty-eight".