261620547 has 4 divisors (see below), whose sum is σ = 348827400. Its totient is φ = 174413696.

The previous prime is 261620509. The next prime is 261620551. The reversal of 261620547 is 745026162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261620547 - 2¹⁴ = 261604163 is a prime.

It is a super-2 number, since 2×261620547² = 136890621225158418, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261620507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43603422 + ... + 43603427.

It is an arithmetic number, because the mean of its divisors is an integer number (87206850).

Almost surely, 2^261620547 is an apocalyptic number.

261620547 is a deficient number, since it is larger than the sum of its proper divisors (87206853).

261620547 is an equidigital number, since it uses as much as digits as its factorization.

261620547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87206852.

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 261620547 is about 16174.6884668608. The cubic root of 261620547 is about 639.5737290040.

The spelling of 261620547 in words is "two hundred sixty-one million, six hundred twenty thousand, five hundred forty-seven".