21092107 has 4 divisors (see below), whose sum is σ = 21210120. Its totient is φ = 20974096.

The previous prime is 21092101. The next prime is 21092117. The reversal of 21092107 is 70129012.

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

It is a cyclic number.

It is not a de Polignac number, because 21092107 - 2⁷ = 21091979 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21092101) 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, 58738 + ... + 59095.

It is an arithmetic number, because the mean of its divisors is an integer number (5302530).

Almost surely, 2^21092107 is an apocalyptic number.

21092107 is a deficient number, since it is larger than the sum of its proper divisors (118013).

21092107 is a wasteful number, since it uses less digits than its factorization.

21092107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118012.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 21092107 is about 4592.6143970510. The cubic root of 21092107 is about 276.2951884473.

The spelling of 21092107 in words is "twenty-one million, ninety-two thousand, one hundred seven".