1551561156656 has 20 divisors (see below), whose sum is σ = 3435599704272. Its totient is φ = 664954781376.

The previous prime is 1551561156637. The next prime is 1551561156689. The reversal of 1551561156656 is 6566511651551.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1551561156598 and 1551561156607.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6926612195 + ... + 6926612418.

Almost surely, 2^{1551561156656} is an apocalyptic number.

1551561156656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1551561156656 is an abundant number, since it is smaller than the sum of its proper divisors (1884038547616).

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

1551561156656 is a wasteful number, since it uses less digits than its factorization.

1551561156656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13853224628 (or 13853224622 counting only the distinct ones).

The product of its digits is 4050000, while the sum is 53.

The spelling of 1551561156656 in words is "one trillion, five hundred fifty-one billion, five hundred sixty-one million, one hundred fifty-six thousand, six hundred fifty-six".