21115502425031 has 12 divisors (see below), whose sum is σ = 26007809710608. Its totient is φ = 17034354896832.

The previous prime is 21115502425007. The next prime is 21115502425057. The reversal of 21115502425031 is 13052420551112.

It is not a de Polignac number, because 21115502425031 - 2¹⁰ = 21115502424007 is a prime.

It is a super-2 number, since 2×21115502425031² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115502424031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12674370371 + ... + 12674372036.

It is an arithmetic number, because the mean of its divisors is an integer number (2167317475884).

Almost surely, 2^{21115502425031} is an apocalyptic number.

21115502425031 is a deficient number, since it is larger than the sum of its proper divisors (4892307285577).

21115502425031 is a wasteful number, since it uses less digits than its factorization.

21115502425031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25348742438 (or 25348742431 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 32.

Adding to 21115502425031 its reverse (13052420551112), we get a palindrome (34167922976143).

The spelling of 21115502425031 in words is "twenty-one trillion, one hundred fifteen billion, five hundred two million, four hundred twenty-five thousand, thirty-one".