21346021051 has 4 divisors (see below), whose sum is σ = 21346639432. Its totient is φ = 21345402672.

The previous prime is 21346021027. The next prime is 21346021087. The reversal of 21346021051 is 15012064312.

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 21346021051 - 2¹⁵ = 21345988283 is a prime.

It is a super-2 number, since 2×21346021051² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21346021351) 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, 254145 + ... + 327538.

It is an arithmetic number, because the mean of its divisors is an integer number (5336659858).

Almost surely, 2^21346021051 is an apocalyptic number.

21346021051 is a deficient number, since it is larger than the sum of its proper divisors (618381).

21346021051 is an equidigital number, since it uses as much as digits as its factorization.

21346021051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618380.

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 21346021051 its reverse (15012064312), we get a palindrome (36358085363).

The spelling of 21346021051 in words is "twenty-one billion, three hundred forty-six million, twenty-one thousand, fifty-one".