20749778 has 8 divisors (see below), whose sum is σ = 35571072. Its totient is φ = 8892756.

The previous prime is 20749777. The next prime is 20749787. The reversal of 20749778 is 87794702.

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 (20749777) 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, 741050 + ... + 741077.

It is an arithmetic number, because the mean of its divisors is an integer number (4446384).

Almost surely, 2^20749778 is an apocalyptic number.

20749778 is a deficient number, since it is larger than the sum of its proper divisors (14821294).

20749778 is a wasteful number, since it uses less digits than its factorization.

20749778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1482136.

The product of its (nonzero) digits is 197568, while the sum is 44.

The square root of 20749778 is about 4555.1924218413. The cubic root of 20749778 is about 274.7922530158.

The spelling of 20749778 in words is "twenty million, seven hundred forty-nine thousand, seven hundred seventy-eight".