21001504142 has 24 divisors (see below), whose sum is σ = 32651002800. Its totient is φ = 10130888768.

The previous prime is 21001504141. The next prime is 21001504201. The reversal of 21001504142 is 24140510012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001504141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2618234 + ... + 2626242.

It is an arithmetic number, because the mean of its divisors is an integer number (1360458450).

Almost surely, 2^21001504142 is an apocalyptic number.

21001504142 is a deficient number, since it is larger than the sum of its proper divisors (11649498658).

21001504142 is a wasteful number, since it uses less digits than its factorization.

21001504142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9628 (or 9599 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The spelling of 21001504142 in words is "twenty-one billion, one million, five hundred four thousand, one hundred forty-two".