1981187026 has 32 divisors (see below), whose sum is σ = 3783709440. Its totient is φ = 756737856.

The previous prime is 1981186973. The next prime is 1981187027. The reversal of 1981187026 is 6207811891.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1981187027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182406 + ... + 192961.

It is an arithmetic number, because the mean of its divisors is an integer number (118240920).

Almost surely, 2^1981187026 is an apocalyptic number.

1981187026 is a deficient number, since it is larger than the sum of its proper divisors (1802522414).

1981187026 is a wasteful number, since it uses less digits than its factorization.

1981187026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375418.

The product of its (nonzero) digits is 48384, while the sum is 43.

The square root of 1981187026 is about 44510.5271368471. The cubic root of 1981187026 is about 1255.9581210596.

The spelling of 1981187026 in words is "one billion, nine hundred eighty-one million, one hundred eighty-seven thousand, twenty-six".