402981 has 4 divisors (see below), whose sum is σ = 537312. Its totient is φ = 268652.

The previous prime is 402949. The next prime is 402991. The reversal of 402981 is 189204.

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 a cyclic number.

It is not a de Polignac number, because 402981 - 2⁵ = 402949 is a prime.

It is a super-2 number, since 2×402981² = 324787372722, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

It is a plaindrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 402981.

It is not an unprimeable number, because it can be changed into a prime (402991) 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, 67161 + ... + 67166.

It is an arithmetic number, because the mean of its divisors is an integer number (134328).

2⁴⁰²⁹⁸¹ is an apocalyptic number.

It is an amenable number.

402981 is a deficient number, since it is larger than the sum of its proper divisors (134331).

402981 is a wasteful number, since it uses less digits than its factorization.

402981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134330.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 402981 is about 634.8078449421. The cubic root of 402981 is about 73.8632121216.

The spelling of 402981 in words is "four hundred two thousand, nine hundred eighty-one".