1661560690990 has 64 divisors (see below), whose sum is σ = 3081050265600. Its totient is φ = 644869345536.

The previous prime is 1661560690987. The next prime is 1661560691057. The reversal of 1661560690990 is 990960651661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 231508282 + ... + 231515458.

It is an arithmetic number, because the mean of its divisors is an integer number (48141410400).

Almost surely, 2^{1661560690990} is an apocalyptic number.

1661560690990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661560690990 is a deficient number, since it is larger than the sum of its proper divisors (1419489574610).

1661560690990 is a wasteful number, since it uses less digits than its factorization.

1661560690990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12289.

The product of its (nonzero) digits is 4723920, while the sum is 58.

The spelling of 1661560690990 in words is "one trillion, six hundred sixty-one billion, five hundred sixty million, six hundred ninety thousand, nine hundred ninety".