869801981 has 4 divisors (see below), whose sum is σ = 869860992. Its totient is φ = 869742972.

The previous prime is 869801951. The next prime is 869801987. The reversal of 869801981 is 189108968.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-869801981 is a prime.

It is a super-2 number, since 2×869801981² = 1513110972303048722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869801987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13460 + ... + 43826.

It is an arithmetic number, because the mean of its divisors is an integer number (217465248).

Almost surely, 2^869801981 is an apocalyptic number.

It is an amenable number.

869801981 is a deficient number, since it is larger than the sum of its proper divisors (59011).

869801981 is a wasteful number, since it uses less digits than its factorization.

869801981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59010.

The product of its (nonzero) digits is 248832, while the sum is 50.

The square root of 869801981 is about 29492.4054800554. The cubic root of 869801981 is about 954.5678375047.

The spelling of 869801981 in words is "eight hundred sixty-nine million, eight hundred one thousand, nine hundred eighty-one".