21049775 has 24 divisors (see below), whose sum is σ = 27272064. Its totient is φ = 16099200.

The previous prime is 21049759. The next prime is 21049783. The reversal of 21049775 is 57794012.

It is not a de Polignac number, because 21049775 - 2⁴ = 21049759 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 121589 + ... + 121761.

It is an arithmetic number, because the mean of its divisors is an integer number (1136336).

Almost surely, 2^21049775 is an apocalyptic number.

21049775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21049775 is a deficient number, since it is larger than the sum of its proper divisors (6222289).

21049775 is a wasteful number, since it uses less digits than its factorization.

21049775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 21049775 is about 4588.0033783771. The cubic root of 21049775 is about 276.1102225516.

The spelling of 21049775 in words is "twenty-one million, forty-nine thousand, seven hundred seventy-five".