20901778 has 8 divisors (see below), whose sum is σ = 31376268. Its totient is φ = 10443024.

The previous prime is 20901763. The next prime is 20901791. The reversal of 20901778 is 87710902.

It can be written as a sum of positive squares in 2 ways, for example, as 17614809 + 3286969 = 4197^2 + 1813^2 .

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

It is a super-2 number, since 2×20901778² = 873768647122568, which contains 22 as substring.

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, 300 + ... + 6472.

Almost surely, 2^20901778 is an apocalyptic number.

20901778 is a deficient number, since it is larger than the sum of its proper divisors (10474490).

20901778 is a wasteful number, since it uses less digits than its factorization.

20901778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7868.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20901778 is about 4571.8462353846. The cubic root of 20901778 is about 275.4616070952.

The spelling of 20901778 in words is "twenty million, nine hundred one thousand, seven hundred seventy-eight".