1930639661 has 4 divisors (see below), whose sum is σ = 1939789824. Its totient is φ = 1921489500.

The previous prime is 1930639657. The next prime is 1930639681. The reversal of 1930639661 is 1669360391.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1930639661 - 2² = 1930639657 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 (1930639681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4574765 + ... + 4575186.

It is an arithmetic number, because the mean of its divisors is an integer number (484947456).

Almost surely, 2^1930639661 is an apocalyptic number.

It is an amenable number.

1930639661 is a deficient number, since it is larger than the sum of its proper divisors (9150163).

1930639661 is an equidigital number, since it uses as much as digits as its factorization.

1930639661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150162.

The product of its (nonzero) digits is 157464, while the sum is 44.

The square root of 1930639661 is about 43939.0448348619. The cubic root of 1930639661 is about 1245.1846010471.

The spelling of 1930639661 in words is "one billion, nine hundred thirty million, six hundred thirty-nine thousand, six hundred sixty-one".