21151318207 has 2 divisors, whose sum is σ = 21151318208. Its totient is φ = 21151318206.

The previous prime is 21151318183. The next prime is 21151318241. The reversal of 21151318207 is 70281315112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21151318207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21151318267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575659103 + 10575659104.

It is an arithmetic number, because the mean of its divisors is an integer number (10575659104).

Almost surely, 2^21151318207 is an apocalyptic number.

21151318207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21151318207 is an equidigital number, since it uses as much as digits as its factorization.

21151318207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 31.

The spelling of 21151318207 in words is "twenty-one billion, one hundred fifty-one million, three hundred eighteen thousand, two hundred seven".