401231861 has 2 divisors, whose sum is σ = 401231862. Its totient is φ = 401231860.

The previous prime is 401231851. The next prime is 401231879. The reversal of 401231861 is 168132104.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 273406225 + 127825636 = 16535^2 + 11306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-401231861 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 401231861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401231821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200615930 + 200615931.

It is an arithmetic number, because the mean of its divisors is an integer number (200615931).

Almost surely, 2^401231861 is an apocalyptic number.

It is an amenable number.

401231861 is a deficient number, since it is larger than the sum of its proper divisors (1).

401231861 is an equidigital number, since it uses as much as digits as its factorization.

401231861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 401231861 is about 20030.7728507914. The cubic root of 401231861 is about 737.5618937234.

Adding to 401231861 its reverse (168132104), we get a palindrome (569363965).

The spelling of 401231861 in words is "four hundred one million, two hundred thirty-one thousand, eight hundred sixty-one".