20561010 has 16 divisors (see below), whose sum is σ = 49346496. Its totient is φ = 5482928.

The previous prime is 20560999. The next prime is 20561017. The reversal of 20561010 is 1016502.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20561017) 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, 342654 + ... + 342713.

It is an arithmetic number, because the mean of its divisors is an integer number (3084156).

Almost surely, 2^20561010 is an apocalyptic number.

20561010 is an abundant number, since it is smaller than the sum of its proper divisors (28785486).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20561010 is a wasteful number, since it uses less digits than its factorization.

20561010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685377.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 20561010 is about 4534.4249911097. The cubic root of 20561010 is about 273.9564194456.

Adding to 20561010 its reverse (1016502), we get a palindrome (21577512).

The spelling of 20561010 in words is "twenty million, five hundred sixty-one thousand, ten".