21873707 has 2 divisors, whose sum is σ = 21873708. Its totient is φ = 21873706.

The previous prime is 21873673. The next prime is 21873721. The reversal of 21873707 is 70737812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21873707 - 2⁸ = 21873451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21873727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936853 + 10936854.

It is an arithmetic number, because the mean of its divisors is an integer number (10936854).

Almost surely, 2^21873707 is an apocalyptic number.

21873707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873707 is an equidigital number, since it uses as much as digits as its factorization.

21873707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16464, while the sum is 35.

The square root of 21873707 is about 4676.9335039104. The cubic root of 21873707 is about 279.6667250697. Note that the first 3 decimals are identical.

The spelling of 21873707 in words is "twenty-one million, eight hundred seventy-three thousand, seven hundred seven".