402143981 has 4 divisors (see below), whose sum is σ = 403412892. Its totient is φ = 400875072.

The previous prime is 402143977. The next prime is 402143999. The reversal of 402143981 is 189341204.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 167288356 + 234855625 = 12934^2 + 15325^2 .

It is a cyclic number.

It is not a de Polignac number, because 402143981 - 2² = 402143977 is a prime.

It is a super-2 number, since 2×402143981² = 323439562909056722, 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 (402143281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 633980 + ... + 634613.

It is an arithmetic number, because the mean of its divisors is an integer number (100853223).

Almost surely, 2^402143981 is an apocalyptic number.

It is an amenable number.

402143981 is a deficient number, since it is larger than the sum of its proper divisors (1268911).

402143981 is a wasteful number, since it uses less digits than its factorization.

402143981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1268910.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 402143981 is about 20053.5278941138. The cubic root of 402143981 is about 738.1203703212.

The spelling of 402143981 in words is "four hundred two million, one hundred forty-three thousand, nine hundred eighty-one".