205725990 has 16 divisors (see below), whose sum is σ = 493742448. Its totient is φ = 54860256.

The previous prime is 205725983. The next prime is 205726009. The reversal of 205725990 is 99527502.

It is a super-2 number, since 2×205725990² = 84646365922960200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3428737 + ... + 3428796.

It is an arithmetic number, because the mean of its divisors is an integer number (30858903).

Almost surely, 2^205725990 is an apocalyptic number.

205725990 is an abundant number, since it is smaller than the sum of its proper divisors (288016458).

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

205725990 is a wasteful number, since it uses less digits than its factorization.

205725990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6857543.

The product of its (nonzero) digits is 56700, while the sum is 39.

The square root of 205725990 is about 14343.1513273757. The cubic root of 205725990 is about 590.3320834710.

It can be divided in two parts, 20572 and 5990, that added together give a palindrome (26562).

The spelling of 205725990 in words is "two hundred five million, seven hundred twenty-five thousand, nine hundred ninety".