401375661 has 32 divisors (see below), whose sum is σ = 576004608. Its totient is φ = 247726080.

The previous prime is 401375647. The next prime is 401375677. The reversal of 401375661 is 166573104.

It is not a de Polignac number, because 401375661 - 2¹⁷ = 401244589 is a prime.

It is a super-2 number, since 2×401375661² = 322204842486373842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401375641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1480956 + ... + 1481226.

It is an arithmetic number, because the mean of its divisors is an integer number (18000144).

Almost surely, 2^401375661 is an apocalyptic number.

It is an amenable number.

401375661 is a deficient number, since it is larger than the sum of its proper divisors (174628947).

401375661 is a wasteful number, since it uses less digits than its factorization.

401375661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 401375661 is about 20034.3620063131. The cubic root of 401375661 is about 737.6499963415.

The spelling of 401375661 in words is "four hundred one million, three hundred seventy-five thousand, six hundred sixty-one".