1971779158 has 16 divisors (see below), whose sum is σ = 3003480000. Its totient is φ = 970712512.

The previous prime is 1971779143. The next prime is 1971779209. The reversal of 1971779158 is 8519771791.

It is a junction number, because it is equal to n+sod(n) for n = 1971779099 and 1971779108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19368 + ... + 65716.

It is an arithmetic number, because the mean of its divisors is an integer number (187717500).

Almost surely, 2^1971779158 is an apocalyptic number.

1971779158 is a deficient number, since it is larger than the sum of its proper divisors (1031700842).

1971779158 is a wasteful number, since it uses less digits than its factorization.

1971779158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46679.

The product of its digits is 1111320, while the sum is 55.

The square root of 1971779158 is about 44404.7199968652. The cubic root of 1971779158 is about 1253.9669510286.

The spelling of 1971779158 in words is "one billion, nine hundred seventy-one million, seven hundred seventy-nine thousand, one hundred fifty-eight".