1997511642 has 24 divisors (see below), whose sum is σ = 4946219616. Its totient is φ = 570717576.

The previous prime is 1997511623. The next prime is 1997511661. The reversal of 1997511642 is 2461157991.

1997511642 is a `hidden beast` number, since 1 + 9 + 97 + 511 + 6 + 42 = 666.

It is an interprime number because it is at equal distance from previous prime (1997511623) and next prime (1997511661).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7926508 + ... + 7926759.

It is an arithmetic number, because the mean of its divisors is an integer number (206092484).

Almost surely, 2^1997511642 is an apocalyptic number.

1997511642 is an abundant number, since it is smaller than the sum of its proper divisors (2948707974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1997511642 is a wasteful number, since it uses less digits than its factorization.

1997511642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15853282 (or 15853279 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 1997511642 is about 44693.5302029276. The cubic root of 1997511642 is about 1259.3983106038.

The spelling of 1997511642 in words is "one billion, nine hundred ninety-seven million, five hundred eleven thousand, six hundred forty-two".