16161777616 has 30 divisors (see below), whose sum is σ = 31407688130. Its totient is φ = 8056640448.

The previous prime is 16161777613. The next prime is 16161777629. The reversal of 16161777616 is 61677716161.

It can be written as a sum of positive squares in only one way, i.e., 15605006400 + 556771216 = 124920^2 + 23596^2 .

It is a super-2 number, since 2×16161777616² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16161777616.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16161777613) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1922350 + ... + 1930738.

Almost surely, 2^16161777616 is an apocalyptic number.

16161777616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

16161777616 is a deficient number, since it is larger than the sum of its proper divisors (15245910514).

16161777616 is an frugal number, since it uses more digits than its factorization.

16161777616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9091 (or 8738 counting only the distinct ones).

The product of its digits is 444528, while the sum is 49.

The spelling of 16161777616 in words is "sixteen billion, one hundred sixty-one million, seven hundred seventy-seven thousand, six hundred sixteen".