400121040 has 80 divisors (see below), whose sum is σ = 1353145536. Its totient is φ = 96998400.

The previous prime is 400121039. The next prime is 400121069. The reversal of 400121040 is 40121004.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73141 + ... + 78420.

Almost surely, 2^400121040 is an apocalyptic number.

400121040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400121040 is an abundant number, since it is smaller than the sum of its proper divisors (953024496).

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

400121040 is a wasteful number, since it uses less digits than its factorization.

400121040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151588 (or 151582 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 400121040 is about 20003.0257711177. The cubic root of 400121040 is about 736.8806114284.

Adding to 400121040 its reverse (40121004), we get a palindrome (440242044).

The spelling of 400121040 in words is "four hundred million, one hundred twenty-one thousand, forty".