21158003 has 2 divisors, whose sum is σ = 21158004. Its totient is φ = 21158002.

The previous prime is 21157993. The next prime is 21158041. The reversal of 21158003 is 30085112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21158003 - 2⁴ = 21157987 is a prime.

It is a super-2 number, since 2×21158003² = 895322181896018, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21158063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10579001 + 10579002.

It is an arithmetic number, because the mean of its divisors is an integer number (10579002).

Almost surely, 2^21158003 is an apocalyptic number.

21158003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21158003 is an equidigital number, since it uses as much as digits as its factorization.

21158003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21158003 is about 4599.7829296609. The cubic root of 21158003 is about 276.5826233009.

The spelling of 21158003 in words is "twenty-one million, one hundred fifty-eight thousand, three".