261218245 has 32 divisors (see below), whose sum is σ = 345047040. Its totient is φ = 189203520.

The previous prime is 261218231. The next prime is 261218263. The reversal of 261218245 is 542812162.

It is not a de Polignac number, because 261218245 - 2⁷ = 261218117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 166776 + ... + 168334.

It is an arithmetic number, because the mean of its divisors is an integer number (10782720).

Almost surely, 2^261218245 is an apocalyptic number.

It is an amenable number.

261218245 is a deficient number, since it is larger than the sum of its proper divisors (83828795).

261218245 is a wasteful number, since it uses less digits than its factorization.

261218245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665.

The product of its digits is 7680, while the sum is 31.

The square root of 261218245 is about 16162.2475231634. The cubic root of 261218245 is about 639.2457300592.

The spelling of 261218245 in words is "two hundred sixty-one million, two hundred eighteen thousand, two hundred forty-five".