20021620545 has 24 divisors (see below), whose sum is σ = 36745563816. Its totient is φ = 10050067968.

The previous prime is 20021620529. The next prime is 20021620571. The reversal of 20021620545 is 54502612002.

20021620545 is a `hidden beast` number, since 200 + 216 + 205 + 45 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 655001649 + 19366618896 = 25593^2 + 139164^2 .

It is not a de Polignac number, because 20021620545 - 2⁴ = 20021620529 is a prime.

It is a super-3 number, since 3×20021620545³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13085262 + ... + 13086791.

It is an arithmetic number, because the mean of its divisors is an integer number (1531065159).

Almost surely, 2^20021620545 is an apocalyptic number.

It is an amenable number.

20021620545 is a deficient number, since it is larger than the sum of its proper divisors (16723943271).

20021620545 is a wasteful number, since it uses less digits than its factorization.

20021620545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26172081 (or 26172078 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The spelling of 20021620545 in words is "twenty billion, twenty-one million, six hundred twenty thousand, five hundred forty-five".