1971997515 has 16 divisors (see below), whose sum is σ = 3505773600. Its totient is φ = 1051731936.

The previous prime is 1971997507. The next prime is 1971997537. The reversal of 1971997515 is 5157991791.

It is not a de Polignac number, because 1971997515 - 2³ = 1971997507 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7303560 + ... + 7303829.

It is an arithmetic number, because the mean of its divisors is an integer number (219110850).

Almost surely, 2^1971997515 is an apocalyptic number.

1971997515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1971997515 is a deficient number, since it is larger than the sum of its proper divisors (1533776085).

1971997515 is a wasteful number, since it uses less digits than its factorization.

1971997515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14607403 (or 14607397 counting only the distinct ones).

The product of its digits is 893025, while the sum is 54.

The square root of 1971997515 is about 44407.1786426474. The cubic root of 1971997515 is about 1254.0132378814.

The spelling of 1971997515 in words is "one billion, nine hundred seventy-one million, nine hundred ninety-seven thousand, five hundred fifteen".