20731330 has 16 divisors (see below), whose sum is σ = 39511800. Its totient is φ = 7804672.

The previous prime is 20731327. The next prime is 20731339. The reversal of 20731330 is 3313702.

It can be written as a sum of positive squares in 4 ways, for example, as 15992001 + 4739329 = 3999^2 + 2177^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20731298 and 20731307.

It is not an unprimeable number, because it can be changed into a prime (20731339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60805 + ... + 61144.

Almost surely, 2^20731330 is an apocalyptic number.

20731330 is a deficient number, since it is larger than the sum of its proper divisors (18780470).

20731330 is a wasteful number, since it uses less digits than its factorization.

20731330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121973.

The product of its (nonzero) digits is 378, while the sum is 19.

The square root of 20731330 is about 4553.1670296619. The cubic root of 20731330 is about 274.7107923761.

It can be divided in two parts, 2073 and 1330, that added together give a triangular number (3403 = T₈₂).

The spelling of 20731330 in words is "twenty million, seven hundred thirty-one thousand, three hundred thirty".