20667681555 has 16 divisors (see below), whose sum is σ = 34135010304. Its totient is φ = 10667190240.

The previous prime is 20667681539. The next prime is 20667681557. The reversal of 20667681555 is 55518676602.

It is a happy number.

It is not a de Polignac number, because 20667681555 - 2⁴ = 20667681539 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20667681498 and 20667681507.

It is not an unprimeable number, because it can be changed into a prime (20667681557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22222849 + ... + 22223778.

It is an arithmetic number, because the mean of its divisors is an integer number (2133438144).

Almost surely, 2^20667681555 is an apocalyptic number.

20667681555 is a deficient number, since it is larger than the sum of its proper divisors (13467328749).

20667681555 is a wasteful number, since it uses less digits than its factorization.

20667681555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44446666.

The product of its (nonzero) digits is 3024000, while the sum is 51.

The spelling of 20667681555 in words is "twenty billion, six hundred sixty-seven million, six hundred eighty-one thousand, five hundred fifty-five".