21775351 has 16 divisors (see below), whose sum is σ = 25510464. Its totient is φ = 18399744.

The previous prime is 21775339. The next prime is 21775357. The reversal of 21775351 is 15357712.

It is a cyclic number.

It is not a de Polignac number, because 21775351 - 2¹⁵ = 21742583 is a prime.

It is a super-2 number, since 2×21775351² = 948331822346402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21775357) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6846 + ... + 9508.

It is an arithmetic number, because the mean of its divisors is an integer number (1594404).

Almost surely, 2^21775351 is an apocalyptic number.

21775351 is a deficient number, since it is larger than the sum of its proper divisors (3735113).

21775351 is a wasteful number, since it uses less digits than its factorization.

21775351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2730.

The product of its digits is 7350, while the sum is 31.

The square root of 21775351 is about 4666.4066475180. The cubic root of 21775351 is about 279.2469176674.

The spelling of 21775351 in words is "twenty-one million, seven hundred seventy-five thousand, three hundred fifty-one".