21603070021 has 8 divisors (see below), whose sum is σ = 24067081080. Its totient is φ = 19253664192.

The previous prime is 21603070019. The next prime is 21603070033. The reversal of 21603070021 is 12007030612.

It can be written as a sum of positive squares in 4 ways, for example, as 8767521 + 21594302500 = 2961^2 + 146950^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21603070021 - 2¹ = 21603070019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21603069974 and 21603070001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21603070051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28650910 + ... + 28651663.

It is an arithmetic number, because the mean of its divisors is an integer number (3008385135).

Almost surely, 2^21603070021 is an apocalyptic number.

It is an amenable number.

21603070021 is a deficient number, since it is larger than the sum of its proper divisors (2464011059).

21603070021 is a wasteful number, since it uses less digits than its factorization.

21603070021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57302615.

The product of its (nonzero) digits is 504, while the sum is 22.

The spelling of 21603070021 in words is "twenty-one billion, six hundred three million, seventy thousand, twenty-one".