261887028851 has 8 divisors (see below), whose sum is σ = 299313197664. Its totient is φ = 224464294080.

The previous prime is 261887028743. The next prime is 261887028877. The reversal of 261887028851 is 158820788162.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261887028851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261887028251) 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, 692960 + ... + 1001981.

It is an arithmetic number, because the mean of its divisors is an integer number (37414149708).

Almost surely, 2^261887028851 is an apocalyptic number.

261887028851 is a deficient number, since it is larger than the sum of its proper divisors (37426168813).

261887028851 is a wasteful number, since it uses less digits than its factorization.

261887028851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1717021.

The product of its (nonzero) digits is 3440640, while the sum is 56.

The spelling of 261887028851 in words is "two hundred sixty-one billion, eight hundred eighty-seven million, twenty-eight thousand, eight hundred fifty-one".