20406421003644 has 54 divisors (see below), whose sum is σ = 55856036994576. Its totient is φ = 6278898768480.

The previous prime is 20406421003589. The next prime is 20406421003693. The reversal of 20406421003644 is 44630012460402.

20406421003644 is a `hidden beast` number, since 2 + 0 + 4 + 0 + 6 + 4 + 2 + 1 + 0 + 0 + 3 + 644 = 666.

It is a super-2 number, since 2×20406421003644² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20406421003599 and 20406421003608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1677050212 + ... + 1677062379.

Almost surely, 2^{20406421003644} is an apocalyptic number.

It is an amenable number.

20406421003644 is an abundant number, since it is smaller than the sum of its proper divisors (35449615990932).

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

20406421003644 is a wasteful number, since it uses less digits than its factorization.

20406421003644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3354112627 (or 3354112609 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The spelling of 20406421003644 in words is "twenty trillion, four hundred six billion, four hundred twenty-one million, three thousand, six hundred forty-four".