20661388454 has 32 divisors (see below), whose sum is σ = 36101604096. Its totient is φ = 8684488800.

The previous prime is 20661388439. The next prime is 20661388469. The reversal of 20661388454 is 45488316602.

It is an interprime number because it is at equal distance from previous prime (20661388439) and next prime (20661388469).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20661388399 and 20661388408.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3448049 + ... + 3454035.

It is an arithmetic number, because the mean of its divisors is an integer number (1128175128).

Almost surely, 2^20661388454 is an apocalyptic number.

20661388454 is a deficient number, since it is larger than the sum of its proper divisors (15440215642).

20661388454 is a wasteful number, since it uses less digits than its factorization.

20661388454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10700.

The product of its (nonzero) digits is 1105920, while the sum is 47.

The spelling of 20661388454 in words is "twenty billion, six hundred sixty-one million, three hundred eighty-eight thousand, four hundred fifty-four".