261950031 has 60 divisors (see below), whose sum is σ = 470099520. Its totient is φ = 144789120.

The previous prime is 261949997. The next prime is 261950053. The reversal of 261950031 is 130059162.

It is not a de Polignac number, because 261950031 - 2¹⁰ = 261949007 is a prime.

It is a super-2 number, since 2×261950031² = 137235637481801922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 261949977 and 261950004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261950071) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 121975 + ... + 124103.

It is an arithmetic number, because the mean of its divisors is an integer number (7834992).

Almost surely, 2^261950031 is an apocalyptic number.

261950031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

261950031 is a deficient number, since it is larger than the sum of its proper divisors (208149489).

261950031 is a wasteful number, since it uses less digits than its factorization.

261950031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2186 (or 2170 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 261950031 is about 16184.8704350699. The cubic root of 261950031 is about 639.8421086743.

It can be divided in two parts, 2619 and 50031, that added together give a triangular number (52650 = T₃₂₄).

The spelling of 261950031 in words is "two hundred sixty-one million, nine hundred fifty thousand, thirty-one".