1982400691 has 2 divisors, whose sum is σ = 1982400692. Its totient is φ = 1982400690.

The previous prime is 1982400671. The next prime is 1982400781. The reversal of 1982400691 is 1960042891.

It is a weak prime.

It is an emirp because it is prime and its reverse (1960042891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1982400691 - 2⁹ = 1982400179 is a prime.

It is not a weakly prime, because it can be changed into another prime (1982400671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 991200345 + 991200346.

It is an arithmetic number, because the mean of its divisors is an integer number (991200346).

Almost surely, 2^1982400691 is an apocalyptic number.

1982400691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1982400691 is an equidigital number, since it uses as much as digits as its factorization.

1982400691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 1982400691 is about 44524.1585097349. The cubic root of 1982400691 is about 1256.2145332066.

The spelling of 1982400691 in words is "one billion, nine hundred eighty-two million, four hundred thousand, six hundred ninety-one".