1687561172 has 24 divisors (see below), whose sum is σ = 3230240160. Its totient is φ = 765041760.

The previous prime is 1687561159. The next prime is 1687561237. The reversal of 1687561172 is 2711657861.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33923 + ... + 67274.

It is an arithmetic number, because the mean of its divisors is an integer number (134593340).

Almost surely, 2^1687561172 is an apocalyptic number.

It is an amenable number.

1687561172 is a deficient number, since it is larger than the sum of its proper divisors (1542678988).

1687561172 is a wasteful number, since it uses less digits than its factorization.

1687561172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101591 (or 101589 counting only the distinct ones).

The product of its digits is 141120, while the sum is 44.

The square root of 1687561172 is about 41079.9363680130. The cubic root of 1687561172 is about 1190.5651746538.

The spelling of 1687561172 in words is "one billion, six hundred eighty-seven million, five hundred sixty-one thousand, one hundred seventy-two".