21601954 has 16 divisors (see below), whose sum is σ = 35425440. Its totient is φ = 9797760.

The previous prime is 21601949. The next prime is 21601967. The reversal of 21601954 is 45910612.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14077 + ... + 15535.

It is an arithmetic number, because the mean of its divisors is an integer number (2214090).

Almost surely, 2^21601954 is an apocalyptic number.

21601954 is a deficient number, since it is larger than the sum of its proper divisors (13823486).

21601954 is a wasteful number, since it uses less digits than its factorization.

21601954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2145.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21601954 is about 4647.7902276243. The cubic root of 21601954 is about 278.5037276011.

It can be divided in two parts, 2160 and 1954, that added together give a palindrome (4114).

The spelling of 21601954 in words is "twenty-one million, six hundred one thousand, nine hundred fifty-four".