21053430501 has 4 divisors (see below), whose sum is σ = 28071240672. Its totient is φ = 14035620332.

The previous prime is 21053430499. The next prime is 21053430533. The reversal of 21053430501 is 10503435012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21053430501 - 2¹ = 21053430499 is a prime.

It is a super-2 number, since 2×21053430501² (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 (21053430571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3508905081 + ... + 3508905086.

It is an arithmetic number, because the mean of its divisors is an integer number (7017810168).

Almost surely, 2^21053430501 is an apocalyptic number.

It is an amenable number.

21053430501 is a deficient number, since it is larger than the sum of its proper divisors (7017810171).

21053430501 is an equidigital number, since it uses as much as digits as its factorization.

21053430501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7017810170.

The product of its (nonzero) digits is 1800, while the sum is 24.

Adding to 21053430501 its reverse (10503435012), we get a palindrome (31556865513).

The spelling of 21053430501 in words is "twenty-one billion, fifty-three million, four hundred thirty thousand, five hundred one".