1978156201 has 8 divisors (see below), whose sum is σ = 2261663424. Its totient is φ = 1694877360.

The previous prime is 1978156171. The next prime is 1978156231. The reversal of 1978156201 is 1026518791.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1978156171) and next prime (1978156231).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1978156201 - 2⁷ = 1978156073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978156231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38110 + ... + 73543.

It is an arithmetic number, because the mean of its divisors is an integer number (282707928).

Almost surely, 2^1978156201 is an apocalyptic number.

It is an amenable number.

1978156201 is a deficient number, since it is larger than the sum of its proper divisors (283507223).

1978156201 is a wasteful number, since it uses less digits than its factorization.

1978156201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114191.

The product of its (nonzero) digits is 30240, while the sum is 40.

The square root of 1978156201 is about 44476.4679465445. The cubic root of 1978156201 is about 1255.3173382051.

The spelling of 1978156201 in words is "one billion, nine hundred seventy-eight million, one hundred fifty-six thousand, two hundred one".