161626021 has 16 divisors (see below), whose sum is σ = 174666240. Its totient is φ = 149011200.

The previous prime is 161625979. The next prime is 161626039. The reversal of 161626021 is 120626161.

161626021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 161626021 - 2¹⁵ = 161593253 is a prime.

It is a super-2 number, since 2×161626021² = 52245941328584882, which 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 (161626721) 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, 202395 + ... + 203191.

It is an arithmetic number, because the mean of its divisors is an integer number (10916640).

Almost surely, 2^161626021 is an apocalyptic number.

It is an amenable number.

161626021 is a deficient number, since it is larger than the sum of its proper divisors (13040219).

161626021 is a wasteful number, since it uses less digits than its factorization.

161626021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 161626021 is about 12713.2222901985. Note that the first 4 decimals coincide. The cubic root of 161626021 is about 544.7163701077.

The spelling of 161626021 in words is "one hundred sixty-one million, six hundred twenty-six thousand, twenty-one".