402891649 has 2 divisors, whose sum is σ = 402891650. Its totient is φ = 402891648.

The previous prime is 402891617. The next prime is 402891677. The reversal of 402891649 is 946198204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 402283249 + 608400 = 20057^2 + 780^2 .

It is a cyclic number.

It is not a de Polignac number, because 402891649 - 2⁵ = 402891617 is a prime.

It is not a weakly prime, because it can be changed into another prime (402891689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201445824 + 201445825.

It is an arithmetic number, because the mean of its divisors is an integer number (201445825).

Almost surely, 2^402891649 is an apocalyptic number.

It is an amenable number.

402891649 is a deficient number, since it is larger than the sum of its proper divisors (1).

402891649 is an equidigital number, since it uses as much as digits as its factorization.

402891649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 402891649 is about 20072.1610445911. The cubic root of 402891649 is about 738.5775260891.

The spelling of 402891649 in words is "four hundred two million, eight hundred ninety-one thousand, six hundred forty-nine".