20261890 has 16 divisors (see below), whose sum is σ = 39787200. Its totient is φ = 7367920.

The previous prime is 20261881. The next prime is 20261897. The reversal of 20261890 is 9816202.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20261897) 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, 91990 + ... + 92209.

It is an arithmetic number, because the mean of its divisors is an integer number (2486700).

Almost surely, 2^20261890 is an apocalyptic number.

20261890 is a deficient number, since it is larger than the sum of its proper divisors (19525310).

20261890 is a wasteful number, since it uses less digits than its factorization.

20261890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184217.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20261890 is about 4501.3209172420. The cubic root of 20261890 is about 272.6214255584.

It can be divided in two parts, 2026 and 1890, that added together give a triangular number (3916 = T₈₈).

The spelling of 20261890 in words is "twenty million, two hundred sixty-one thousand, eight hundred ninety".