21402102031 has 4 divisors (see below), whose sum is σ = 21857465952. Its totient is φ = 20946738112.

The previous prime is 21402101983. The next prime is 21402102041. The reversal of 21402102031 is 13020120412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21402102031 - 2¹⁷ = 21401970959 is a prime.

It is a super-2 number, since 2×21402102031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21402101996 and 21402102014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402102041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227681890 + ... + 227681983.

It is an arithmetic number, because the mean of its divisors is an integer number (5464366488).

Almost surely, 2^21402102031 is an apocalyptic number.

21402102031 is a deficient number, since it is larger than the sum of its proper divisors (455363921).

21402102031 is an equidigital number, since it uses as much as digits as its factorization.

21402102031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455363920.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21402102031 its reverse (13020120412), we get a palindrome (34422222443).

The spelling of 21402102031 in words is "twenty-one billion, four hundred two million, one hundred two thousand, thirty-one".