20719405646 has 32 divisors (see below), whose sum is σ = 34041461760. Its totient is φ = 9424355616.

The previous prime is 20719405631. The next prime is 20719405661. The reversal of 20719405646 is 64650491702.

It is an interprime number because it is at equal distance from previous prime (20719405631) and next prime (20719405661).

It is a junction number, because it is equal to n+sod(n) for n = 20719405597 and 20719405606.

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, 14786 + ... + 204101.

It is an arithmetic number, because the mean of its divisors is an integer number (1063795680).

Almost surely, 2^20719405646 is an apocalyptic number.

20719405646 is a deficient number, since it is larger than the sum of its proper divisors (13322056114).

20719405646 is a wasteful number, since it uses less digits than its factorization.

20719405646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219008.

The product of its (nonzero) digits is 362880, while the sum is 44.

The spelling of 20719405646 in words is "twenty billion, seven hundred nineteen million, four hundred five thousand, six hundred forty-six".