20513090 has 16 divisors (see below), whose sum is σ = 39764088. Its totient is φ = 7574016.

The previous prime is 20513083. The next prime is 20513093. The reversal of 20513090 is 9031502.

It can be written as a sum of positive squares in 4 ways, for example, as 12823561 + 7689529 = 3581^2 + 2773^2 .

It is a super-2 number, since 2×20513090² = 841573722696200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20513093) 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, 78767 + ... + 79026.

Almost surely, 2^20513090 is an apocalyptic number.

20513090 is a deficient number, since it is larger than the sum of its proper divisors (19250998).

20513090 is a wasteful number, since it uses less digits than its factorization.

20513090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157813.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 20513090 is about 4529.1378870597. The cubic root of 20513090 is about 273.7434240131.

Adding to 20513090 its reverse (9031502), we get a palindrome (29544592).

The spelling of 20513090 in words is "twenty million, five hundred thirteen thousand, ninety".