1971427988 has 6 divisors (see below), whose sum is σ = 3449998986. Its totient is φ = 985713992.

The previous prime is 1971427979. The next prime is 1971427993. The reversal of 1971427988 is 8897241791.

It can be written as a sum of positive squares in only one way, i.e., 1968874384 + 2553604 = 44372^2 + 1598^2 .

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, 246428495 + ... + 246428502.

It is an arithmetic number, because the mean of its divisors is an integer number (574999831).

Almost surely, 2^1971427988 is an apocalyptic number.

It is an amenable number.

1971427988 is a deficient number, since it is larger than the sum of its proper divisors (1478570998).

1971427988 is a wasteful number, since it uses less digits than its factorization.

1971427988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492857001 (or 492856999 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 56.

The square root of 1971427988 is about 44400.7656240295. The cubic root of 1971427988 is about 1253.8925035907.

The spelling of 1971427988 in words is "one billion, nine hundred seventy-one million, four hundred twenty-seven thousand, nine hundred eighty-eight".