402278381 has 2 divisors, whose sum is σ = 402278382. Its totient is φ = 402278380.

The previous prime is 402278369. The next prime is 402278411. The reversal of 402278381 is 183872204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 287980900 + 114297481 = 16970^2 + 10691^2 .

It is a cyclic number.

It is not a de Polignac number, because 402278381 - 2²² = 398084077 is a prime.

It is a super-2 number, since 2×402278381² = 323655791639962322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402274381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201139190 + 201139191.

It is an arithmetic number, because the mean of its divisors is an integer number (201139191).

Almost surely, 2^402278381 is an apocalyptic number.

It is an amenable number.

402278381 is a deficient number, since it is larger than the sum of its proper divisors (1).

402278381 is an equidigital number, since it uses as much as digits as its factorization.

402278381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 402278381 is about 20056.8786454922. The cubic root of 402278381 is about 738.2025899017.

The spelling of 402278381 in words is "four hundred two million, two hundred seventy-eight thousand, three hundred eighty-one".