21053051 has 2 divisors, whose sum is σ = 21053052. Its totient is φ = 21053050.

The previous prime is 21053041. The next prime is 21053059. The reversal of 21053051 is 15035012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21053051 is a prime.

It is not a weakly prime, because it can be changed into another prime (21053059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10526525 + 10526526.

It is an arithmetic number, because the mean of its divisors is an integer number (10526526).

Almost surely, 2^21053051 is an apocalyptic number.

21053051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21053051 is an equidigital number, since it uses as much as digits as its factorization.

21053051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 21053051 is about 4588.3603825332. The cubic root of 21053051 is about 276.1245455894.

Adding to 21053051 its reverse (15035012), we get a palindrome (36088063).

The spelling of 21053051 in words is "twenty-one million, fifty-three thousand, fifty-one".