400001616 has 120 divisors (see below), whose sum is σ = 1292875584. Its totient is φ = 113080320.

The previous prime is 400001603. The next prime is 400001621. The reversal of 400001616 is 616100004.

It is a super-2 number, since 2×400001616² = 320002585605222912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95731 + ... + 99821.

Almost surely, 2^400001616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400001616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (646437792).

400001616 is an abundant number, since it is smaller than the sum of its proper divisors (892873968).

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

400001616 is a wasteful number, since it uses less digits than its factorization.

400001616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4209 (or 4200 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 400001616 is about 20000.0403999592. The cubic root of 400001616 is about 736.8072919592.

It can be divided in two parts, 40000 and 1616, that added together give a triangular number (41616 = T₂₈₈).

The spelling of 400001616 in words is "four hundred million, one thousand, six hundred sixteen".