21431420525 has 24 divisors (see below), whose sum is σ = 27141700320. Its totient is φ = 16781061440.

The previous prime is 21431420509. The next prime is 21431420531. The reversal of 21431420525 is 52502413412.

It is not a de Polignac number, because 21431420525 - 2⁴ = 21431420509 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 535874 + ... + 574476.

It is an arithmetic number, because the mean of its divisors is an integer number (1130904180).

Almost surely, 2^21431420525 is an apocalyptic number.

21431420525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21431420525 is a deficient number, since it is larger than the sum of its proper divisors (5710279795).

21431420525 is a wasteful number, since it uses less digits than its factorization.

21431420525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39085 (or 39080 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 21431420525 its reverse (52502413412), we get a palindrome (73933833937).

The spelling of 21431420525 in words is "twenty-one billion, four hundred thirty-one million, four hundred twenty thousand, five hundred twenty-five".