21340642442 has 16 divisors (see below), whose sum is σ = 37024731072. Its totient is φ = 9035796480.

The previous prime is 21340642439. The next prime is 21340642447. The reversal of 21340642442 is 24424604312.

It is a junction number, because it is equal to n+sod(n) for n = 21340642399 and 21340642408.

It is not an unprimeable number, because it can be changed into a prime (21340642447) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9181559 + ... + 9183882.

It is an arithmetic number, because the mean of its divisors is an integer number (2314045692).

Almost surely, 2^21340642442 is an apocalyptic number.

21340642442 is a deficient number, since it is larger than the sum of its proper divisors (15684088630).

21340642442 is a wasteful number, since it uses less digits than its factorization.

21340642442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18365533.

The product of its (nonzero) digits is 36864, while the sum is 32.

The spelling of 21340642442 in words is "twenty-one billion, three hundred forty million, six hundred forty-two thousand, four hundred forty-two".