21120421031 has 8 divisors (see below), whose sum is σ = 21265468800. Its totient is φ = 20975762808.

The previous prime is 21120421001. The next prime is 21120421051. The reversal of 21120421031 is 13012402112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21120421031 - 2²² = 21116226727 is a prime.

It is a super-2 number, since 2×21120421031² (a number of 21 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 (21120421001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11840 + ... + 205866.

It is an arithmetic number, because the mean of its divisors is an integer number (2658183600).

Almost surely, 2^21120421031 is an apocalyptic number.

21120421031 is a deficient number, since it is larger than the sum of its proper divisors (145047769).

21120421031 is a wasteful number, since it uses less digits than its factorization.

21120421031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194773.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21120421031 its reverse (13012402112), we get a palindrome (34132823143).

The spelling of 21120421031 in words is "twenty-one billion, one hundred twenty million, four hundred twenty-one thousand, thirty-one".