21356212001051 has 4 divisors (see below), whose sum is σ = 21364037658600. Its totient is φ = 21348386343504.

The previous prime is 21356212001029. The next prime is 21356212001057. The reversal of 21356212001051 is 15010021265312.

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 21356212001051 - 2³⁴ = 21339032131867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21356212001057) 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, 3912824681 + ... + 3912830138.

It is an arithmetic number, because the mean of its divisors is an integer number (5341009414650).

Almost surely, 2^{21356212001051} is an apocalyptic number.

21356212001051 is a deficient number, since it is larger than the sum of its proper divisors (7825657549).

21356212001051 is an equidigital number, since it uses as much as digits as its factorization.

21356212001051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7825657548.

The product of its (nonzero) digits is 3600, while the sum is 29.

Adding to 21356212001051 its reverse (15010021265312), we get a palindrome (36366233266363).

The spelling of 21356212001051 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred twelve million, one thousand, fifty-one".