21770975 has 12 divisors (see below), whose sum is σ = 27212544. Its totient is φ = 17277120.

The previous prime is 21770963. The next prime is 21770981. The reversal of 21770975 is 57907712.

It is a de Polignac number, because none of the positive numbers 2^k-21770975 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 254 + ... + 6603.

It is an arithmetic number, because the mean of its divisors is an integer number (2267712).

Almost surely, 2^21770975 is an apocalyptic number.

21770975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21770975 is a deficient number, since it is larger than the sum of its proper divisors (5441569).

21770975 is a wasteful number, since it uses less digits than its factorization.

21770975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6994 (or 6989 counting only the distinct ones).

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 21770975 is about 4665.9377406905. The cubic root of 21770975 is about 279.2282104852.

The spelling of 21770975 in words is "twenty-one million, seven hundred seventy thousand, nine hundred seventy-five".