261878628 has 24 divisors (see below), whose sum is σ = 666600480. Its totient is φ = 79357120.

The previous prime is 261878623. The next prime is 261878629. The reversal of 261878628 is 826878162.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (261878623) 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, 991833 + ... + 992096.

It is an arithmetic number, because the mean of its divisors is an integer number (27775020).

Almost surely, 2^261878628 is an apocalyptic number.

It is an amenable number.

261878628 is an abundant number, since it is smaller than the sum of its proper divisors (404721852).

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

261878628 is a wasteful number, since it uses less digits than its factorization.

261878628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983947 (or 1983945 counting only the distinct ones).

The product of its digits is 516096, while the sum is 48.

The square root of 261878628 is about 16182.6644283319. The cubic root of 261878628 is about 639.7839667993.

The spelling of 261878628 in words is "two hundred sixty-one million, eight hundred seventy-eight thousand, six hundred twenty-eight".