20949907 has 4 divisors (see below), whose sum is σ = 22854456. Its totient is φ = 19045360.

The previous prime is 20949883. The next prime is 20949917. The reversal of 20949907 is 70994902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20949907 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20949907.

It is not an unprimeable number, because it can be changed into a prime (20949917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 952258 + ... + 952279.

It is an arithmetic number, because the mean of its divisors is an integer number (5713614).

Almost surely, 2^20949907 is an apocalyptic number.

20949907 is a deficient number, since it is larger than the sum of its proper divisors (1904549).

20949907 is a wasteful number, since it uses less digits than its factorization.

20949907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1904548.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 20949907 is about 4577.1068372936. The cubic root of 20949907 is about 275.6728734740.

The spelling of 20949907 in words is "twenty million, nine hundred forty-nine thousand, nine hundred seven".