1987391968 has 12 divisors (see below), whose sum is σ = 3912678000. Its totient is φ = 993695968.

The previous prime is 1987391957. The next prime is 1987391993. The reversal of 1987391968 is 8691937891.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31052968 + ... + 31053031.

It is an arithmetic number, because the mean of its divisors is an integer number (326056500).

Almost surely, 2^1987391968 is an apocalyptic number.

It is an amenable number.

1987391968 is a deficient number, since it is larger than the sum of its proper divisors (1925286032).

1987391968 is an equidigital number, since it uses as much as digits as its factorization.

1987391968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62106009 (or 62106001 counting only the distinct ones).

The product of its digits is 5878656, while the sum is 61.

The square root of 1987391968 is about 44580.1746071053. The cubic root of 1987391968 is about 1257.2679461716.

The spelling of 1987391968 in words is "one billion, nine hundred eighty-seven million, three hundred ninety-one thousand, nine hundred sixty-eight".