981642261 has 4 divisors (see below), whose sum is σ = 1308856352. Its totient is φ = 654428172.

The previous prime is 981642241. The next prime is 981642269. The reversal of 981642261 is 162246189.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 981642261 - 2¹⁰ = 981641237 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 (981642269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163607041 + ... + 163607046.

It is an arithmetic number, because the mean of its divisors is an integer number (327214088).

Almost surely, 2^981642261 is an apocalyptic number.

It is an amenable number.

981642261 is a deficient number, since it is larger than the sum of its proper divisors (327214091).

981642261 is a wasteful number, since it uses less digits than its factorization.

981642261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327214090.

The product of its digits is 41472, while the sum is 39.

The square root of 981642261 is about 31331.1707569315. The cubic root of 981642261 is about 993.8429218596.

The spelling of 981642261 in words is "nine hundred eighty-one million, six hundred forty-two thousand, two hundred sixty-one".