21204620651442 has 16 divisors (see below), whose sum is σ = 42475196584800. Its totient is φ = 7057214336832.

The previous prime is 21204620651413. The next prime is 21204620651453. The reversal of 21204620651442 is 24415602640212.

It is a super-3 number, since 3×21204620651442³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21204620651442.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2748132567 + ... + 2748140282.

It is an arithmetic number, because the mean of its divisors is an integer number (2654699786550).

Almost surely, 2^{21204620651442} is an apocalyptic number.

21204620651442 is an abundant number, since it is smaller than the sum of its proper divisors (21270575933358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21204620651442 is a wasteful number, since it uses less digits than its factorization.

21204620651442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5496273497.

The product of its (nonzero) digits is 184320, while the sum is 39.

The spelling of 21204620651442 in words is "twenty-one trillion, two hundred four billion, six hundred twenty million, six hundred fifty-one thousand, four hundred forty-two".