21101407 has 2 divisors, whose sum is σ = 21101408. Its totient is φ = 21101406.

The previous prime is 21101401. The next prime is 21101411. The reversal of 21101407 is 70410112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21101407 - 2¹⁹ = 20577119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550703 + 10550704.

It is an arithmetic number, because the mean of its divisors is an integer number (10550704).

Almost surely, 2^21101407 is an apocalyptic number.

21101407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101407 is an equidigital number, since it uses as much as digits as its factorization.

21101407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21101407 is about 4593.6267806604. The cubic root of 21101407 is about 276.3357908029.

Adding to 21101407 its reverse (70410112), we get a palindrome (91511519).

The spelling of 21101407 in words is "twenty-one million, one hundred one thousand, four hundred seven".