21870240071 has 4 divisors (see below), whose sum is σ = 21874267992. Its totient is φ = 21866212152.

The previous prime is 21870240047. The next prime is 21870240089. The reversal of 21870240071 is 17004207812.

It is a happy number.

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 21870240071 - 2²² = 21866045767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21870240001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2005805 + ... + 2016678.

It is an arithmetic number, because the mean of its divisors is an integer number (5468566998).

Almost surely, 2^21870240071 is an apocalyptic number.

21870240071 is a deficient number, since it is larger than the sum of its proper divisors (4027921).

21870240071 is an equidigital number, since it uses as much as digits as its factorization.

21870240071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4027920.

The product of its (nonzero) digits is 6272, while the sum is 32.

Adding to 21870240071 its reverse (17004207812), we get a palindrome (38874447883).

The spelling of 21870240071 in words is "twenty-one billion, eight hundred seventy million, two hundred forty thousand, seventy-one".