22778491 has 4 divisors (see below), whose sum is σ = 22790800. Its totient is φ = 22766184.

The previous prime is 22778489. The next prime is 22778507. The reversal of 22778491 is 19487722.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19487722 = 2 ⋅9743861.

It is a cyclic number.

It is not a de Polignac number, because 22778491 - 2¹ = 22778489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22775491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2751 + ... + 7288.

It is an arithmetic number, because the mean of its divisors is an integer number (5697700).

Almost surely, 2^22778491 is an apocalyptic number.

22778491 is a deficient number, since it is larger than the sum of its proper divisors (12309).

22778491 is a wasteful number, since it uses less digits than its factorization.

22778491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12308.

The product of its digits is 56448, while the sum is 40.

The square root of 22778491 is about 4772.6817409084. The cubic root of 22778491 is about 283.4707917407.

The spelling of 22778491 in words is "twenty-two million, seven hundred seventy-eight thousand, four hundred ninety-one".