21542071007 has 2 divisors, whose sum is σ = 21542071008. Its totient is φ = 21542071006.

The previous prime is 21542070989. The next prime is 21542071043. The reversal of 21542071007 is 70017024512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21542071007 - 2⁶ = 21542070943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21542071097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771035503 + 10771035504.

It is an arithmetic number, because the mean of its divisors is an integer number (10771035504).

Almost surely, 2^21542071007 is an apocalyptic number.

21542071007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21542071007 is an equidigital number, since it uses as much as digits as its factorization.

21542071007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 29.

Adding to 21542071007 its reverse (70017024512), we get a palindrome (91559095519).

The spelling of 21542071007 in words is "twenty-one billion, five hundred forty-two million, seventy-one thousand, seven".