261493820 has 24 divisors (see below), whose sum is σ = 627585504. Its totient is φ = 89654976.

The previous prime is 261493819. The next prime is 261493849. The reversal of 261493820 is 28394162.

261493820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

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, 933767 + ... + 934046.

It is an arithmetic number, because the mean of its divisors is an integer number (26149396).

Almost surely, 2^261493820 is an apocalyptic number.

261493820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261493820 is an abundant number, since it is smaller than the sum of its proper divisors (366091684).

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

261493820 is a wasteful number, since it uses less digits than its factorization.

261493820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1867829 (or 1867827 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 261493820 is about 16170.7705444113. The cubic root of 261493820 is about 639.4704441113.

The spelling of 261493820 in words is "two hundred sixty-one million, four hundred ninety-three thousand, eight hundred twenty".