401620021 has 16 divisors (see below), whose sum is σ = 448908480. Its totient is φ = 356222080.

The previous prime is 401620007. The next prime is 401620027. The reversal of 401620021 is 120026104.

It is a cyclic number.

It is not a de Polignac number, because 401620021 - 2⁵ = 401619989 is a prime.

It is a super-2 number, since 2×401620021² = 322597282536080882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 401619977 and 401620004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401620027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86655 + ... + 91171.

It is an arithmetic number, because the mean of its divisors is an integer number (28056780).

Almost surely, 2^401620021 is an apocalyptic number.

It is an amenable number.

401620021 is a deficient number, since it is larger than the sum of its proper divisors (47288459).

401620021 is a wasteful number, since it uses less digits than its factorization.

401620021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4724.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 401620021 is about 20040.4596005181. The cubic root of 401620021 is about 737.7996612759.

Adding to 401620021 its reverse (120026104), we get a palindrome (521646125).

The spelling of 401620021 in words is "four hundred one million, six hundred twenty thousand, twenty-one".