21492151 has 2 divisors, whose sum is σ = 21492152. Its totient is φ = 21492150.

The previous prime is 21492067. The next prime is 21492157. The reversal of 21492151 is 15129412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21492151 - 2¹¹ = 21490103 is a prime.

It is equal to p_1359160 and since 21492151 and 1359160 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21492157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10746075 + 10746076.

It is an arithmetic number, because the mean of its divisors is an integer number (10746076).

Almost surely, 2^21492151 is an apocalyptic number.

21492151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21492151 is an equidigital number, since it uses as much as digits as its factorization.

21492151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 21492151 is about 4635.9627910500. The cubic root of 21492151 is about 278.0310465128.

The spelling of 21492151 in words is "twenty-one million, four hundred ninety-two thousand, one hundred fifty-one".