21601021053 has 16 divisors (see below), whose sum is σ = 29137021056. Its totient is φ = 14233390080.

The previous prime is 21601021051. The next prime is 21601021063. The reversal of 21601021053 is 35012010612.

It is not a de Polignac number, because 21601021053 - 2¹ = 21601021051 is a prime.

It is a super-2 number, since 2×21601021053² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21601021051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93901 + ... + 228077.

It is an arithmetic number, because the mean of its divisors is an integer number (1821063816).

Almost surely, 2^21601021053 is an apocalyptic number.

It is an amenable number.

21601021053 is a deficient number, since it is larger than the sum of its proper divisors (7536000003).

21601021053 is a wasteful number, since it uses less digits than its factorization.

21601021053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134804.

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 21601021053 its reverse (35012010612), we get a palindrome (56613031665).

The spelling of 21601021053 in words is "twenty-one billion, six hundred one million, twenty-one thousand, fifty-three".