21320131642 has 16 divisors (see below), whose sum is σ = 33314688000. Its totient is φ = 10221545520.

The previous prime is 21320131631. The next prime is 21320131687. The reversal of 21320131642 is 24613102312.

It is an unprimeable number.

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, 1570642 + ... + 1584157.

It is an arithmetic number, because the mean of its divisors is an integer number (2082168000).

Almost surely, 2^21320131642 is an apocalyptic number.

21320131642 is a deficient number, since it is larger than the sum of its proper divisors (11994556358).

21320131642 is a wasteful number, since it uses less digits than its factorization.

21320131642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3154941.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21320131642 its reverse (24613102312), we get a palindrome (45933233954).

The spelling of 21320131642 in words is "twenty-one billion, three hundred twenty million, one hundred thirty-one thousand, six hundred forty-two".