401689993949 has 4 divisors (see below), whose sum is σ = 402460992540. Its totient is φ = 400918995360.

The previous prime is 401689993927. The next prime is 401689993973. The reversal of 401689993949 is 949399986104.

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

It can be written as a sum of positive squares in 2 ways, for example, as 74640972025 + 327049021924 = 273205^2 + 571882^2 .

It is a cyclic number.

It is not a de Polignac number, because 401689993949 - 2¹⁶ = 401689928413 is a prime.

It is a super-2 number, since 2×401689993949² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401689993049) 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, 385498514 + ... + 385499555.

It is an arithmetic number, because the mean of its divisors is an integer number (100615248135).

Almost surely, 2^401689993949 is an apocalyptic number.

It is an amenable number.

401689993949 is a deficient number, since it is larger than the sum of its proper divisors (770998591).

401689993949 is an equidigital number, since it uses as much as digits as its factorization.

401689993949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770998590.

The product of its (nonzero) digits is 136048896, while the sum is 71.

The spelling of 401689993949 in words is "four hundred one billion, six hundred eighty-nine million, nine hundred ninety-three thousand, nine hundred forty-nine".