21651534442 has 8 divisors (see below), whose sum is σ = 32489834436. Its totient is φ = 10821589632.

The previous prime is 21651534391. The next prime is 21651534467. The reversal of 21651534442 is 24443515612.

It can be written as a sum of positive squares in 2 ways, for example, as 21100177081 + 551357361 = 145259^2 + 23481^2 .

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

It is a super-2 number, since 2×21651534442² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2082313 + ... + 2092684.

Almost surely, 2^21651534442 is an apocalyptic number.

21651534442 is a deficient number, since it is larger than the sum of its proper divisors (10838299994).

21651534442 is a wasteful number, since it uses less digits than its factorization.

21651534442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4177592.

The product of its digits is 115200, while the sum is 37.

The spelling of 21651534442 in words is "twenty-one billion, six hundred fifty-one million, five hundred thirty-four thousand, four hundred forty-two".