20513623 has 8 divisors (see below), whose sum is σ = 22605968. Its totient is φ = 18494784.

The previous prime is 20513621. The next prime is 20513627. The reversal of 20513623 is 32631502.

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

It is a cyclic number.

It is not a de Polignac number, because 20513623 - 2¹ = 20513621 is a prime.

It is a super-2 number, since 2×20513623² = 841617457172258, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20513594 and 20513603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513621) 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, 17790 + ... + 18907.

It is an arithmetic number, because the mean of its divisors is an integer number (2825746).

Almost surely, 2^20513623 is an apocalyptic number.

20513623 is a deficient number, since it is larger than the sum of its proper divisors (2092345).

20513623 is a wasteful number, since it uses less digits than its factorization.

20513623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36753.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 20513623 is about 4529.1967278978. The cubic root of 20513623 is about 273.7457949216.

The spelling of 20513623 in words is "twenty million, five hundred thirteen thousand, six hundred twenty-three".