1661057837504 has 56 divisors (see below), whose sum is σ = 3594645754560. Its totient is φ = 756937718784.

The previous prime is 1661057837501. The next prime is 1661057837507. The reversal of 1661057837504 is 4057387501661.

It is an interprime number because it is at equal distance from previous prime (1661057837501) and next prime (1661057837507).

It is a super-2 number, since 2×1661057837504² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661057837501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12570119 + ... + 12701574.

It is an arithmetic number, because the mean of its divisors is an integer number (64190102760).

Almost surely, 2^{1661057837504} is an apocalyptic number.

It is an amenable number.

1661057837504 is an abundant number, since it is smaller than the sum of its proper divisors (1933587917056).

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

1661057837504 is a wasteful number, since it uses less digits than its factorization.

1661057837504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25271797 (or 25271787 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 53.

The spelling of 1661057837504 in words is "one trillion, six hundred sixty-one billion, fifty-seven million, eight hundred thirty-seven thousand, five hundred four".