20857384 has 8 divisors (see below), whose sum is σ = 39107610. Its totient is φ = 10428688.

The previous prime is 20857373. The next prime is 20857387. The reversal of 20857384 is 48375802.

It can be written as a sum of positive squares in only one way, i.e., 15920100 + 4937284 = 3990^2 + 2222^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (20857387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1303579 + ... + 1303594.

Almost surely, 2^20857384 is an apocalyptic number.

It is an amenable number.

20857384 is a deficient number, since it is larger than the sum of its proper divisors (18250226).

20857384 is a wasteful number, since it uses less digits than its factorization.

20857384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2607179 (or 2607175 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 20857384 is about 4566.9885044743. The cubic root of 20857384 is about 275.2664480906.

The spelling of 20857384 in words is "twenty million, eight hundred fifty-seven thousand, three hundred eighty-four".