1978880947 has 2 divisors, whose sum is σ = 1978880948. Its totient is φ = 1978880946.

The previous prime is 1978880933. The next prime is 1978880987. The reversal of 1978880947 is 7490888791.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1978880947 - 2⁷ = 1978880819 is a prime.

It is not a weakly prime, because it can be changed into another prime (1978880927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989440473 + 989440474.

It is an arithmetic number, because the mean of its divisors is an integer number (989440474).

Almost surely, 2^1978880947 is an apocalyptic number.

1978880947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978880947 is an equidigital number, since it uses as much as digits as its factorization.

1978880947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8128512, while the sum is 61.

The square root of 1978880947 is about 44484.6147223959. The cubic root of 1978880947 is about 1255.4706249095.

The spelling of 1978880947 in words is "one billion, nine hundred seventy-eight million, eight hundred eighty thousand, nine hundred forty-seven".