15642421031 has 2 divisors, whose sum is σ = 15642421032. Its totient is φ = 15642421030.

The previous prime is 15642421013. The next prime is 15642421063. The reversal of 15642421031 is 13012424651.

Together with previous prime (15642421013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15642421031 - 2³⁰ = 14568679207 is a prime.

It is a super-2 number, since 2×15642421031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 15642420985 and 15642421003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15642426031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7821210515 + 7821210516.

It is an arithmetic number, because the mean of its divisors is an integer number (7821210516).

Almost surely, 2^15642421031 is an apocalyptic number.

15642421031 is a deficient number, since it is larger than the sum of its proper divisors (1).

15642421031 is an equidigital number, since it uses as much as digits as its factorization.

15642421031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 15642421031 its reverse (13012424651), we get a palindrome (28654845682).

The spelling of 15642421031 in words is "fifteen billion, six hundred forty-two million, four hundred twenty-one thousand, thirty-one".