21953051 has 2 divisors, whose sum is σ = 21953052. Its totient is φ = 21953050.

The previous prime is 21953033. The next prime is 21953143. The reversal of 21953051 is 15035912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21953051 - 2¹⁴ = 21936667 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21953051.

It is not a weakly prime, because it can be changed into another prime (21953011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10976525 + 10976526.

It is an arithmetic number, because the mean of its divisors is an integer number (10976526).

Almost surely, 2^21953051 is an apocalyptic number.

21953051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21953051 is an equidigital number, since it uses as much as digits as its factorization.

21953051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 21953051 is about 4685.4083066474. The cubic root of 21953051 is about 280.0044684661.

Adding to 21953051 its reverse (15035912), we get a palindrome (36988963).

The spelling of 21953051 in words is "twenty-one million, nine hundred fifty-three thousand, fifty-one".