20691456634 has 8 divisors (see below), whose sum is σ = 31794189588. Its totient is φ = 10093393440.

The previous prime is 20691456629. The next prime is 20691456641. The reversal of 20691456634 is 43665419602.

It can be written as a sum of positive squares in 2 ways, for example, as 15538370409 + 5153086225 = 124653^2 + 71785^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 126167337 + ... + 126167500.

Almost surely, 2^20691456634 is an apocalyptic number.

20691456634 is a deficient number, since it is larger than the sum of its proper divisors (11102732954).

20691456634 is a wasteful number, since it uses less digits than its factorization.

20691456634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252334880.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 20691456634 in words is "twenty billion, six hundred ninety-one million, four hundred fifty-six thousand, six hundred thirty-four".