21514544381 has 4 divisors (see below), whose sum is σ = 23470412064. Its totient is φ = 19558676700.

The previous prime is 21514544371. The next prime is 21514544383. The reversal of 21514544381 is 18344541512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21514544381 is a prime.

It is a super-2 number, since 2×21514544381² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21514544383) 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 3 ways as a sum of consecutive naturals, for example, 977933825 + ... + 977933846.

It is an arithmetic number, because the mean of its divisors is an integer number (5867603016).

Almost surely, 2^21514544381 is an apocalyptic number.

It is an amenable number.

21514544381 is a deficient number, since it is larger than the sum of its proper divisors (1955867683).

21514544381 is a wasteful number, since it uses less digits than its factorization.

21514544381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1955867682.

The product of its digits is 76800, while the sum is 38.

The spelling of 21514544381 in words is "twenty-one billion, five hundred fourteen million, five hundred forty-four thousand, three hundred eighty-one".