21437021351 has 8 divisors (see below), whose sum is σ = 21490294320. Its totient is φ = 21383777088.

The previous prime is 21437021303. The next prime is 21437021399. The reversal of 21437021351 is 15312073412.

It is an interprime number because it is at equal distance from previous prime (21437021303) and next prime (21437021399).

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-21437021351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21437021051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2636945 + ... + 2645061.

It is an arithmetic number, because the mean of its divisors is an integer number (2686286790).

Almost surely, 2^21437021351 is an apocalyptic number.

21437021351 is a deficient number, since it is larger than the sum of its proper divisors (53272969).

21437021351 is an equidigital number, since it uses as much as digits as its factorization.

21437021351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14353.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 21437021351 its reverse (15312073412), we get a palindrome (36749094763).

The spelling of 21437021351 in words is "twenty-one billion, four hundred thirty-seven million, twenty-one thousand, three hundred fifty-one".