21458051 has 4 divisors (see below), whose sum is σ = 21537504. Its totient is φ = 21378600.

The previous prime is 21458033. The next prime is 21458069. The reversal of 21458051 is 15085412.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21458033) and next prime (21458069).

It is a cyclic number.

It is not a de Polignac number, because 21458051 - 2¹⁰ = 21457027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21458051.

It is not an unprimeable number, because it can be changed into a prime (21458081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39320 + ... + 39861.

It is an arithmetic number, because the mean of its divisors is an integer number (5384376).

Almost surely, 2^21458051 is an apocalyptic number.

21458051 is a deficient number, since it is larger than the sum of its proper divisors (79453).

21458051 is an equidigital number, since it uses as much as digits as its factorization.

21458051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79452.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 21458051 is about 4632.2835621322. The cubic root of 21458051 is about 277.8839249380.

The spelling of 21458051 in words is "twenty-one million, four hundred fifty-eight thousand, fifty-one".