18961670646 has 32 divisors (see below), whose sum is σ = 42389383680. Its totient is φ = 6282706248.

The previous prime is 18961670639. The next prime is 18961670653. The reversal of 18961670646 is 64607616981.

It is a happy number.

18961670646 is a `hidden beast` number, since 18 + 9 + 616 + 7 + 0 + 6 + 4 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (18961670639) and next prime (18961670653).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 18961670592 and 18961670601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1042306 + ... + 1060341.

It is an arithmetic number, because the mean of its divisors is an integer number (1324668240).

Almost surely, 2^18961670646 is an apocalyptic number.

18961670646 is an abundant number, since it is smaller than the sum of its proper divisors (23427713034).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18961670646 is a wasteful number, since it uses less digits than its factorization.

18961670646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102825 (or 2102819 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 18961670646 in words is "eighteen billion, nine hundred sixty-one million, six hundred seventy thousand, six hundred forty-six".