21012115147 has 2 divisors, whose sum is σ = 21012115148. Its totient is φ = 21012115146.

The previous prime is 21012115099. The next prime is 21012115169. The reversal of 21012115147 is 74151121012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012115147 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012175147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506057573 + 10506057574.

It is an arithmetic number, because the mean of its divisors is an integer number (10506057574).

Almost surely, 2^21012115147 is an apocalyptic number.

21012115147 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012115147 is an equidigital number, since it uses as much as digits as its factorization.

21012115147 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 560, while the sum is 25.

Adding to 21012115147 its reverse (74151121012), we get a palindrome (95163236159).

The spelling of 21012115147 in words is "twenty-one billion, twelve million, one hundred fifteen thousand, one hundred forty-seven".