261921450 has 48 divisors (see below), whose sum is σ = 742363200. Its totient is φ = 59867520.

The previous prime is 261921427. The next prime is 261921463. The reversal of 261921450 is 54129162.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123675 + ... + 125774.

It is an arithmetic number, because the mean of its divisors is an integer number (15465900).

Almost surely, 2^261921450 is an apocalyptic number.

261921450 is an abundant number, since it is smaller than the sum of its proper divisors (480441750).

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

261921450 is a wasteful number, since it uses less digits than its factorization.

261921450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249471 (or 249466 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 261921450 is about 16183.9874567425. The cubic root of 261921450 is about 639.8188370699.

The spelling of 261921450 in words is "two hundred sixty-one million, nine hundred twenty-one thousand, four hundred fifty".