261972061 has 8 divisors (see below), whose sum is σ = 283297784. Its totient is φ = 240814080.

The previous prime is 261972043. The next prime is 261972079. The reversal of 261972061 is 160279162.

It is an interprime number because it is at equal distance from previous prime (261972043) and next prime (261972079).

It can be written as a sum of positive squares in 4 ways, for example, as 50851161 + 211120900 = 7131^2 + 14530^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-261972061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261975061) 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, 38676 + ... + 44941.

It is an arithmetic number, because the mean of its divisors is an integer number (35412223).

Almost surely, 2^261972061 is an apocalyptic number.

It is an amenable number.

261972061 is a deficient number, since it is larger than the sum of its proper divisors (21325723).

261972061 is a wasteful number, since it uses less digits than its factorization.

261972061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83871.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 261972061 is about 16185.5509946372. The cubic root of 261972061 is about 639.8600450805.

The spelling of 261972061 in words is "two hundred sixty-one million, nine hundred seventy-two thousand, sixty-one".