21847250431 has 2 divisors, whose sum is σ = 21847250432. Its totient is φ = 21847250430.

The previous prime is 21847250429. The next prime is 21847250497. The reversal of 21847250431 is 13405274812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21847250431 - 2¹ = 21847250429 is a prime.

It is a super-2 number, since 2×21847250431² (a number of 21 digits) contains 22 as substring.

Together with 21847250429, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21847250401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10923625215 + 10923625216.

It is an arithmetic number, because the mean of its divisors is an integer number (10923625216).

Almost surely, 2^21847250431 is an apocalyptic number.

21847250431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21847250431 is an equidigital number, since it uses as much as digits as its factorization.

21847250431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 37.

The spelling of 21847250431 in words is "twenty-one billion, eight hundred forty-seven million, two hundred fifty thousand, four hundred thirty-one".