401990551 has 4 divisors (see below), whose sum is σ = 425637072. Its totient is φ = 378344032.

The previous prime is 401990513. The next prime is 401990579. The reversal of 401990551 is 155099104.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 401990551 - 2¹³ = 401982359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401990851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11823235 + ... + 11823268.

It is an arithmetic number, because the mean of its divisors is an integer number (106409268).

Almost surely, 2^401990551 is an apocalyptic number.

401990551 is a deficient number, since it is larger than the sum of its proper divisors (23646521).

401990551 is a wasteful number, since it uses less digits than its factorization.

401990551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23646520.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 401990551 is about 20049.7020177358. The cubic root of 401990551 is about 738.0264866878.

The spelling of 401990551 in words is "four hundred one million, nine hundred ninety thousand, five hundred fifty-one".