20621450642 has 16 divisors (see below), whose sum is σ = 33508691160. Its totient is φ = 9517590576.

The previous prime is 20621450639. The next prime is 20621450669. The reversal of 20621450642 is 24605412602.

20621450642 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 460574521 + 20160876121 = 21461^2 + 141989^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20621450599 and 20621450608.

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, 2342153 + ... + 2350940.

Almost surely, 2^20621450642 is an apocalyptic number.

20621450642 is a deficient number, since it is larger than the sum of its proper divisors (12887240518).

20621450642 is an equidigital number, since it uses as much as digits as its factorization.

20621450642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4693134 (or 4693108 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The spelling of 20621450642 in words is "twenty billion, six hundred twenty-one million, four hundred fifty thousand, six hundred forty-two".