20556357619 has 32 divisors (see below), whose sum is σ = 25430630400. Its totient is φ = 16215797760.

The previous prime is 20556357607. The next prime is 20556357637. The reversal of 20556357619 is 91675365502.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20556357619 is a prime.

It is a super-2 number, since 2×20556357619² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20556357649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1333347 + ... + 1348675.

It is an arithmetic number, because the mean of its divisors is an integer number (794707200).

Almost surely, 2^20556357619 is an apocalyptic number.

20556357619 is a deficient number, since it is larger than the sum of its proper divisors (4874272781).

20556357619 is a wasteful number, since it uses less digits than its factorization.

20556357619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15603.

The product of its (nonzero) digits is 1701000, while the sum is 49.

The spelling of 20556357619 in words is "twenty billion, five hundred fifty-six million, three hundred fifty-seven thousand, six hundred nineteen".