16651631 has 2 divisors, whose sum is σ = 16651632. Its totient is φ = 16651630.

The previous prime is 16651627. The next prime is 16651637. The reversal of 16651631 is 13615661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16651631 - 2² = 16651627 is a prime.

It is a super-3 number, since 3×16651631³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 16651594 and 16651603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16651637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8325815 + 8325816.

It is an arithmetic number, because the mean of its divisors is an integer number (8325816).

Almost surely, 2^16651631 is an apocalyptic number.

16651631 is a deficient number, since it is larger than the sum of its proper divisors (1).

16651631 is an equidigital number, since it uses as much as digits as its factorization.

16651631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 29.

The square root of 16651631 is about 4080.6410035679. The cubic root of 16651631 is about 255.3596411996.

It can be divided in two parts, 1665 and 1631, that multiplied together give a triangular number (2715615 = T₂₃₃₀).

The spelling of 16651631 in words is "sixteen million, six hundred fifty-one thousand, six hundred thirty-one".