1955201978 has 8 divisors (see below), whose sum is σ = 2940461568. Its totient is φ = 975048124.

The previous prime is 1955201933. The next prime is 1955201987. The reversal of 1955201978 is 8791025591.

It is a happy number.

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

It is a super-2 number, since 2×1955201978² = 7645629549550224968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1275476 + ... + 1277007.

It is an arithmetic number, because the mean of its divisors is an integer number (367557696).

Almost surely, 2^1955201978 is an apocalyptic number.

1955201978 is a deficient number, since it is larger than the sum of its proper divisors (985259590).

1955201978 is a wasteful number, since it uses less digits than its factorization.

1955201978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2552868.

The product of its (nonzero) digits is 226800, while the sum is 47.

The square root of 1955201978 is about 44217.6659040253. The cubic root of 1955201978 is about 1250.4429316707.

The spelling of 1955201978 in words is "one billion, nine hundred fifty-five million, two hundred one thousand, nine hundred seventy-eight".