1521411661 has 16 divisors (see below), whose sum is σ = 1915250688. Its totient is φ = 1173999600.

The previous prime is 1521411629. The next prime is 1521411673. The reversal of 1521411661 is 1661141251.

It is a cyclic number.

It is not a de Polignac number, because 1521411661 - 2⁵ = 1521411629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521411611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87985 + ... + 103846.

It is an arithmetic number, because the mean of its divisors is an integer number (119703168).

Almost surely, 2^1521411661 is an apocalyptic number.

1521411661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1521411661 is a deficient number, since it is larger than the sum of its proper divisors (393839027).

1521411661 is a wasteful number, since it uses less digits than its factorization.

1521411661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191952.

The product of its digits is 1440, while the sum is 28.

The square root of 1521411661 is about 39005.2773480718. The cubic root of 1521411661 is about 1150.1352483654.

The spelling of 1521411661 in words is "one billion, five hundred twenty-one million, four hundred eleven thousand, six hundred sixty-one".