21010350544 has 80 divisors (see below), whose sum is σ = 42378568848. Its totient is φ = 10082451456.

The previous prime is 21010350469. The next prime is 21010350587. The reversal of 21010350544 is 44505301012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 46785600 + 20963564944 = 6840^2 + 144788^2 .

It is a super-2 number, since 2×21010350544² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34052124 + ... + 34052740.

Almost surely, 2^21010350544 is an apocalyptic number.

It is an amenable number.

21010350544 is an abundant number, since it is smaller than the sum of its proper divisors (21368218304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21010350544 is a wasteful number, since it uses less digits than its factorization.

21010350544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352 (or 1346 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21010350544 its reverse (44505301012), we get a palindrome (65515651556).

The spelling of 21010350544 in words is "twenty-one billion, ten million, three hundred fifty thousand, five hundred forty-four".