400921812 has 144 divisors (see below), whose sum is σ = 1172283840. Its totient is φ = 119066112.

The previous prime is 400921811. The next prime is 400921813. The reversal of 400921812 is 218129004.

It is an interprime number because it is at equal distance from previous prime (400921811) and next prime (400921813).

It is a super-3 number, since 3×400921812³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400921811) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 313318 + ... + 314594.

It is an arithmetic number, because the mean of its divisors is an integer number (8140860).

Almost surely, 2^400921812 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 400921812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (586141920).

400921812 is an abundant number, since it is smaller than the sum of its proper divisors (771362028).

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

400921812 is a wasteful number, since it uses less digits than its factorization.

400921812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332 (or 1318 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 400921812 is about 20023.0320381305. The cubic root of 400921812 is about 737.3718629052.

The spelling of 400921812 in words is "four hundred million, nine hundred twenty-one thousand, eight hundred twelve".