21534151 has 2 divisors, whose sum is σ = 21534152. Its totient is φ = 21534150.

The previous prime is 21534089. The next prime is 21534167. The reversal of 21534151 is 15143512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21534151 - 2¹⁷ = 21403079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21534251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767075 + 10767076.

It is an arithmetic number, because the mean of its divisors is an integer number (10767076).

Almost surely, 2^21534151 is an apocalyptic number.

21534151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534151 is an equidigital number, since it uses as much as digits as its factorization.

21534151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 600, while the sum is 22.

The square root of 21534151 is about 4640.4903835694. The cubic root of 21534151 is about 278.2120382556.

Adding to 21534151 its reverse (15143512), we get a palindrome (36677663).

The spelling of 21534151 in words is "twenty-one million, five hundred thirty-four thousand, one hundred fifty-one".