24778222921 has 3 divisors (see below), whose sum is σ = 24778380333. Its totient is φ = 24778065510.

The previous prime is 24778222907. The next prime is 24778222927. The reversal of 24778222921 is 12922287742.

It is a happy number.

The square root of 24778222921 is 157411.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 24778222921 - 2²⁵ = 24744668489 is a prime.

It is a super-2 number, since 2×24778222921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (24778222927) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 78706 + ... + 236116.

It is an arithmetic number, because the mean of its divisors is an integer number (8259460111).

Almost surely, 2^24778222921 is an apocalyptic number.

24778222921 is the 157411-st square number.

24778222921 is the 78706-th centered octagonal number.

It is an amenable number.

24778222921 is a deficient number, since it is larger than the sum of its proper divisors (157412).

24778222921 is an frugal number, since it uses more digits than its factorization.

24778222921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314822 (or 157411 counting only the distinct ones).

The product of its digits is 451584, while the sum is 46.

The spelling of 24778222921 in words is "twenty-four billion, seven hundred seventy-eight million, two hundred twenty-two thousand, nine hundred twenty-one".