1551561664 has 14 divisors (see below), whose sum is σ = 3078880304. Its totient is φ = 775780800.

The previous prime is 1551561619. The next prime is 1551561673. The reversal of 1551561664 is 4661651551.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12121512 + ... + 12121639.

Almost surely, 2^1551561664 is an apocalyptic number.

It is an amenable number.

1551561664 is a deficient number, since it is larger than the sum of its proper divisors (1527318640).

1551561664 is an equidigital number, since it uses as much as digits as its factorization.

1551561664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24243163 (or 24243153 counting only the distinct ones).

The product of its digits is 108000, while the sum is 40.

The square root of 1551561664 is about 39389.8675296072. The cubic root of 1551561664 is about 1157.6830645902.

The spelling of 1551561664 in words is "one billion, five hundred fifty-one million, five hundred sixty-one thousand, six hundred sixty-four".