261403915 has 8 divisors (see below), whose sum is σ = 315610128. Its totient is φ = 207839520.

The previous prime is 261403871. The next prime is 261403939. The reversal of 261403915 is 519304162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261403915 - 2²³ = 253015307 is a prime.

It is a Duffinian 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, 159556 + ... + 161185.

It is an arithmetic number, because the mean of its divisors is an integer number (39451266).

Almost surely, 2^261403915 is an apocalyptic number.

261403915 is a deficient number, since it is larger than the sum of its proper divisors (54206213).

261403915 is a wasteful number, since it uses less digits than its factorization.

261403915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320909.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 261403915 is about 16167.9904440843. The cubic root of 261403915 is about 639.3971496063.

The spelling of 261403915 in words is "two hundred sixty-one million, four hundred three thousand, nine hundred fifteen".