2151691809946 has 48 divisors (see below), whose sum is σ = 3791402095680. Its totient is φ = 913101624960.

The previous prime is 2151691809907. The next prime is 2151691809979. The reversal of 2151691809946 is 6499081961512.

It is a Smith number, since the sum of its digits (61) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11323065 + ... + 11511523.

It is an arithmetic number, because the mean of its divisors is an integer number (78987543660).

Almost surely, 2^{2151691809946} is an apocalyptic number.

2151691809946 is a deficient number, since it is larger than the sum of its proper divisors (1639710285734).

2151691809946 is a wasteful number, since it uses less digits than its factorization.

2151691809946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189619 (or 189612 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 61.

The spelling of 2151691809946 in words is "two trillion, one hundred fifty-one billion, six hundred ninety-one million, eight hundred nine thousand, nine hundred forty-six".