20307778 has 8 divisors (see below), whose sum is σ = 30638268. Its totient is φ = 10095024.

The previous prime is 20307773. The next prime is 20307779. The reversal of 20307778 is 87770302.

It can be written as a sum of positive squares in 2 ways, for example, as 19333609 + 974169 = 4397^2 + 987^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20307773) 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, 29001 + ... + 29692.

Almost surely, 2^20307778 is an apocalyptic number.

20307778 is a deficient number, since it is larger than the sum of its proper divisors (10330490).

20307778 is a wasteful number, since it uses less digits than its factorization.

20307778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58868.

The product of its (nonzero) digits is 16464, while the sum is 34.

The square root of 20307778 is about 4506.4152050161. The cubic root of 20307778 is about 272.8270763280.

It can be divided in two parts, 203077 and 78, that multiplied together give a triangular number (15840006 = T₅₆₂₈).

The spelling of 20307778 in words is "twenty million, three hundred seven thousand, seven hundred seventy-eight".