401781521 has 8 divisors (see below), whose sum is σ = 414099840. Its totient is φ = 389620368.

The previous prime is 401781517. The next prime is 401781533. The reversal of 401781521 is 125187104.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 401781521 - 2² = 401781517 is a prime.

It is a super-2 number, since 2×401781521² = 322856781234146882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (401741521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34091 + ... + 44336.

It is an arithmetic number, because the mean of its divisors is an integer number (51762480).

Almost surely, 2^401781521 is an apocalyptic number.

It is an amenable number.

401781521 is a deficient number, since it is larger than the sum of its proper divisors (12318319).

401781521 is a wasteful number, since it uses less digits than its factorization.

401781521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78583.

The product of its (nonzero) digits is 2240, while the sum is 29.

The square root of 401781521 is about 20044.4885442358. The cubic root of 401781521 is about 737.8985430307.

The spelling of 401781521 in words is "four hundred one million, seven hundred eighty-one thousand, five hundred twenty-one".