21420121420342 has 32 divisors (see below), whose sum is σ = 32946300777600. Its totient is φ = 10438539854400.

The previous prime is 21420121420337. The next prime is 21420121420349. The reversal of 21420121420342 is 24302412102412.

It is a self number, because there is not a number n which added to its sum of digits gives 21420121420342.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420121420349) 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, 573647509 + ... + 573684847.

It is an arithmetic number, because the mean of its divisors is an integer number (1029571899300).

Almost surely, 2^{21420121420342} is an apocalyptic number.

21420121420342 is a deficient number, since it is larger than the sum of its proper divisors (11526179357258).

21420121420342 is a wasteful number, since it uses less digits than its factorization.

21420121420342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44092.

The product of its (nonzero) digits is 6144, while the sum is 28.

Adding to 21420121420342 its reverse (24302412102412), we get a palindrome (45722533522754).

The spelling of 21420121420342 in words is "twenty-one trillion, four hundred twenty billion, one hundred twenty-one million, four hundred twenty thousand, three hundred forty-two".