21122051 has 4 divisors (see below), whose sum is σ = 21139704. Its totient is φ = 21104400.

The previous prime is 21122033. The next prime is 21122069. The reversal of 21122051 is 15022112.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21122033) and next prime (21122069).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122051 is a prime.

It is a super-2 number, since 2×21122051² = 892282076893202, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21122251) 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, 6890 + ... + 9471.

It is an arithmetic number, because the mean of its divisors is an integer number (5284926).

Almost surely, 2^21122051 is an apocalyptic number.

21122051 is a deficient number, since it is larger than the sum of its proper divisors (17653).

21122051 is a wasteful number, since it uses less digits than its factorization.

21122051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17652.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21122051 is about 4595.8732576084. The cubic root of 21122051 is about 276.4258766874.

Adding to 21122051 its reverse (15022112), we get a palindrome (36144163).

The spelling of 21122051 in words is "twenty-one million, one hundred twenty-two thousand, fifty-one".