20778242 has 8 divisors (see below), whose sum is σ = 31395276. Its totient is φ = 10313152.

The previous prime is 20778211. The next prime is 20778253. The reversal of 20778242 is 24287702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19193161 + 1585081 = 4381^2 + 1259^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20778242² = 863470681221128, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20778199 and 20778208.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37643 + ... + 38190.

Almost surely, 2^20778242 is an apocalyptic number.

20778242 is a deficient number, since it is larger than the sum of its proper divisors (10617034).

20778242 is a wasteful number, since it uses less digits than its factorization.

20778242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75972.

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 20778242 is about 4558.3156977112. The cubic root of 20778242 is about 274.9178465343.

The spelling of 20778242 in words is "twenty million, seven hundred seventy-eight thousand, two hundred forty-two".