20929691 has 8 divisors (see below), whose sum is σ = 21518640. Its totient is φ = 20345472.

The previous prime is 20929673. The next prime is 20929693. The reversal of 20929691 is 19692902.

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

It is a cyclic number.

It is not a de Polignac number, because 20929691 - 2²² = 16735387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20929693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8975 + ... + 11063.

It is an arithmetic number, because the mean of its divisors is an integer number (2689830).

Almost surely, 2^20929691 is an apocalyptic number.

20929691 is a deficient number, since it is larger than the sum of its proper divisors (588949).

20929691 is a wasteful number, since it uses less digits than its factorization.

20929691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2365.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 20929691 is about 4574.8979223585. The cubic root of 20929691 is about 275.5841730586.

The spelling of 20929691 in words is "twenty million, nine hundred twenty-nine thousand, six hundred ninety-one".