2151023978 has 8 divisors (see below), whose sum is σ = 3226732740. Its totient is φ = 1075446400.

The previous prime is 2151023977. The next prime is 2151023993. The reversal of 2151023978 is 8793201512.

It can be written as a sum of positive squares in 2 ways, for example, as 2069067169 + 81956809 = 45487^2 + 9053^2 .

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

It is not an unprimeable number, because it can be changed into a prime (2151023977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49178 + ... + 81978.

Almost surely, 2^2151023978 is an apocalyptic number.

2151023978 is a deficient number, since it is larger than the sum of its proper divisors (1075708762).

2151023978 is a wasteful number, since it uses less digits than its factorization.

2151023978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65592.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 2151023978 is about 46379.1330018145. The cubic root of 2151023978 is about 1290.8677489898.

The spelling of 2151023978 in words is "two billion, one hundred fifty-one million, twenty-three thousand, nine hundred seventy-eight".