21054005 has 8 divisors (see below), whose sum is σ = 28874112. Its totient is φ = 14437008.

The previous prime is 21053987. The next prime is 21054017. The reversal of 21054005 is 50045012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21054005 - 2⁶ = 21053941 is a prime.

It is a super-2 number, since 2×21054005² = 886542253080050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300737 + ... + 300806.

It is an arithmetic number, because the mean of its divisors is an integer number (3609264).

Almost surely, 2^21054005 is an apocalyptic number.

It is an amenable number.

21054005 is a deficient number, since it is larger than the sum of its proper divisors (7820107).

21054005 is an equidigital number, since it uses as much as digits as its factorization.

21054005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601555.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 21054005 is about 4588.4643400598. The cubic root of 21054005 is about 276.1287163046.

Adding to 21054005 its reverse (50045012), we get a palindrome (71099017).

The spelling of 21054005 in words is "twenty-one million, fifty-four thousand, five".