21421204007 has 8 divisors (see below), whose sum is σ = 24509171232. Its totient is φ = 18340185600.

The previous prime is 21421203997. The next prime is 21421204009. The reversal of 21421204007 is 70040212412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21421204007 is a prime.

It is a super-2 number, since 2×21421204007² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421204009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1730594 + ... + 1742927.

It is an arithmetic number, because the mean of its divisors is an integer number (3063646404).

Almost surely, 2^21421204007 is an apocalyptic number.

21421204007 is a deficient number, since it is larger than the sum of its proper divisors (3087967225).

21421204007 is an equidigital number, since it uses as much as digits as its factorization.

21421204007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3474409.

The product of its (nonzero) digits is 896, while the sum is 23.

Adding to 21421204007 its reverse (70040212412), we get a palindrome (91461416419).

The spelling of 21421204007 in words is "twenty-one billion, four hundred twenty-one million, two hundred four thousand, seven".