21150139 has 2 divisors, whose sum is σ = 21150140. Its totient is φ = 21150138.

The previous prime is 21150121. The next prime is 21150163. The reversal of 21150139 is 93105112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21150139 - 2⁷ = 21150011 is a prime.

It is not a weakly prime, because it can be changed into another prime (21150739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575069 + 10575070.

It is an arithmetic number, because the mean of its divisors is an integer number (10575070).

Almost surely, 2^21150139 is an apocalyptic number.

21150139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150139 is an equidigital number, since it uses as much as digits as its factorization.

21150139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 21150139 is about 4598.9280272690. The cubic root of 21150139 is about 276.5483523400.

The spelling of 21150139 in words is "twenty-one million, one hundred fifty thousand, one hundred thirty-nine".