1978111465 has 16 divisors (see below), whose sum is σ = 2601156096. Its totient is φ = 1432166400.

The previous prime is 1978111459. The next prime is 1978111511. The reversal of 1978111465 is 5641118791.

It is not a de Polignac number, because 1978111465 - 2⁵ = 1978111433 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68376 + ... + 92905.

It is an arithmetic number, because the mean of its divisors is an integer number (162572256).

Almost surely, 2^1978111465 is an apocalyptic number.

It is an amenable number.

1978111465 is a deficient number, since it is larger than the sum of its proper divisors (623044631).

1978111465 is a wasteful number, since it uses less digits than its factorization.

1978111465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161520.

The product of its digits is 60480, while the sum is 43.

The square root of 1978111465 is about 44475.9650260677. The cubic root of 1978111465 is about 1255.3078751337.

The spelling of 1978111465 in words is "one billion, nine hundred seventy-eight million, one hundred eleven thousand, four hundred sixty-five".