1634507661 has 16 divisors (see below), whose sum is σ = 2299528640. Its totient is φ = 1029853440.

The previous prime is 1634507573. The next prime is 1634507717. The reversal of 1634507661 is 1667054361.

It is not a de Polignac number, because 1634507661 - 2¹⁸ = 1634245517 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1634507561) 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, 10060 + ... + 58053.

It is an arithmetic number, because the mean of its divisors is an integer number (143720540).

Almost surely, 2^1634507661 is an apocalyptic number.

It is an amenable number.

1634507661 is a deficient number, since it is larger than the sum of its proper divisors (665020979).

1634507661 is a wasteful number, since it uses less digits than its factorization.

1634507661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68556.

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 1634507661 is about 40429.0447698186. The cubic root of 1634507661 is about 1177.9557781380.

The spelling of 1634507661 in words is "one billion, six hundred thirty-four million, five hundred seven thousand, six hundred sixty-one".