261031534 has 4 divisors (see below), whose sum is σ = 391547304. Its totient is φ = 130515766.

The previous prime is 261031493. The next prime is 261031541. The reversal of 261031534 is 435130162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 435130162 = 2 ⋅217565081.

It is a junction number, because it is equal to n+sod(n) for n = 261031499 and 261031508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65257882 + ... + 65257885.

It is an arithmetic number, because the mean of its divisors is an integer number (97886826).

Almost surely, 2^261031534 is an apocalyptic number.

261031534 is a deficient number, since it is larger than the sum of its proper divisors (130515770).

261031534 is a wasteful number, since it uses less digits than its factorization.

261031534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130515769.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 261031534 is about 16156.4703447257. The cubic root of 261031534 is about 639.0933891718.

Adding to 261031534 its reverse (435130162), we get a palindrome (696161696).

The spelling of 261031534 in words is "two hundred sixty-one million, thirty-one thousand, five hundred thirty-four".