20778207 has 16 divisors (see below), whose sum is σ = 28512000. Its totient is φ = 13454144.

The previous prime is 20778203. The next prime is 20778211. The reversal of 20778207 is 70287702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20778203) and next prime (20778211).

It is a cyclic number.

It is not a de Polignac number, because 20778207 - 2² = 20778203 is a prime.

It is a super-2 number, since 2×20778207² = 863467772269698, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778203) 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, 15094 + ... + 16412.

It is an arithmetic number, because the mean of its divisors is an integer number (1782000).

Almost surely, 2^20778207 is an apocalyptic number.

20778207 is a deficient number, since it is larger than the sum of its proper divisors (7733793).

20778207 is a wasteful number, since it uses less digits than its factorization.

20778207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1470.

The product of its (nonzero) digits is 10976, while the sum is 33.

The square root of 20778207 is about 4558.3118585722. The cubic root of 20778207 is about 274.9176921720.

The spelling of 20778207 in words is "twenty million, seven hundred seventy-eight thousand, two hundred seven".