21201001051 has 2 divisors, whose sum is σ = 21201001052. Its totient is φ = 21201001050.

The previous prime is 21201001049. The next prime is 21201001057. The reversal of 21201001051 is 15010010212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201001051 - 2¹ = 21201001049 is a prime.

Together with 21201001049, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21201001057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600500525 + 10600500526.

It is an arithmetic number, because the mean of its divisors is an integer number (10600500526).

Almost surely, 2^21201001051 is an apocalyptic number.

21201001051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201001051 is an equidigital number, since it uses as much as digits as its factorization.

21201001051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20, while the sum is 13.

Adding to 21201001051 its reverse (15010010212), we get a palindrome (36211011263).

The spelling of 21201001051 in words is "twenty-one billion, two hundred one million, one thousand, fifty-one".