261206428 has 24 divisors (see below), whose sum is σ = 553144032. Its totient is φ = 105360384.

The previous prime is 261206399. The next prime is 261206447. The reversal of 261206428 is 824602162.

It is a self number, because there is not a number n which added to its sum of digits gives 261206428.

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, 273901 + ... + 274852.

It is an arithmetic number, because the mean of its divisors is an integer number (23047668).

Almost surely, 2^261206428 is an apocalyptic number.

261206428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261206428 is an abundant number, since it is smaller than the sum of its proper divisors (291937604).

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

261206428 is a wasteful number, since it uses less digits than its factorization.

261206428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548781 (or 548779 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 261206428 is about 16161.8819448726. The cubic root of 261206428 is about 639.2360905070.

The spelling of 261206428 in words is "two hundred sixty-one million, two hundred six thousand, four hundred twenty-eight".