16121785810 has 16 divisors (see below), whose sum is σ = 31251461976. Its totient is φ = 5952659328.

The previous prime is 16121785787. The next prime is 16121785811. The reversal of 16121785810 is 1858712161.

It can be written as a sum of positive squares in 4 ways, for example, as 11685826201 + 4435959609 = 108101^2 + 66603^2 .

It is a super-2 number, since 2×16121785810² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16121785811) 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, 62006739 + ... + 62006998.

Almost surely, 2^16121785810 is an apocalyptic number.

16121785810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16121785810 is a deficient number, since it is larger than the sum of its proper divisors (15129676166).

16121785810 is a wasteful number, since it uses less digits than its factorization.

16121785810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124013757.

The product of its (nonzero) digits is 26880, while the sum is 40.

The spelling of 16121785810 in words is "sixteen billion, one hundred twenty-one million, seven hundred eighty-five thousand, eight hundred ten".