20421454306442 has 32 divisors (see below), whose sum is σ = 37338079552128. Its totient is φ = 8177099521536.

The previous prime is 20421454306369. The next prime is 20421454306447. The reversal of 20421454306442 is 24460345412402.

It is a self number, because there is not a number n which added to its sum of digits gives 20421454306442.

It is not an unprimeable number, because it can be changed into a prime (20421454306447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 313122248 + ... + 313187459.

It is an arithmetic number, because the mean of its divisors is an integer number (1166814986004).

Almost surely, 2^{20421454306442} is an apocalyptic number.

20421454306442 is a deficient number, since it is larger than the sum of its proper divisors (16916625245686).

20421454306442 is a wasteful number, since it uses less digits than its factorization.

20421454306442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626309870.

The product of its (nonzero) digits is 737280, while the sum is 41.

Adding to 20421454306442 its reverse (24460345412402), we get a palindrome (44881799718844).

The spelling of 20421454306442 in words is "twenty trillion, four hundred twenty-one billion, four hundred fifty-four million, three hundred six thousand, four hundred forty-two".