20977738 has 8 divisors (see below), whose sum is σ = 31487940. Its totient is φ = 10481760.

The previous prime is 20977709. The next prime is 20977753. The reversal of 20977738 is 83777902.

It can be written as a sum of positive squares in 2 ways, for example, as 16949689 + 4028049 = 4117^2 + 2007^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 20977694 and 20977703.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1668 + ... + 6688.

Almost surely, 2^20977738 is an apocalyptic number.

20977738 is a deficient number, since it is larger than the sum of its proper divisors (10510202).

20977738 is a wasteful number, since it uses less digits than its factorization.

20977738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7112.

The product of its (nonzero) digits is 148176, while the sum is 43.

The square root of 20977738 is about 4580.1460675398. The cubic root of 20977738 is about 275.7948924219.

The spelling of 20977738 in words is "twenty million, nine hundred seventy-seven thousand, seven hundred thirty-eight".