21951402 has 32 divisors (see below), whose sum is σ = 48081600. Its totient is φ = 6625920.

The previous prime is 21951389. The next prime is 21951409. The reversal of 21951402 is 20415912.

It is not an unprimeable number, because it can be changed into a prime (21951409) 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, 22558 + ... + 23510.

It is an arithmetic number, because the mean of its divisors is an integer number (1502550).

Almost surely, 2^21951402 is an apocalyptic number.

21951402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21951402 is an abundant number, since it is smaller than the sum of its proper divisors (26130198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21951402 is a wasteful number, since it uses less digits than its factorization.

21951402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1318.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21951402 is about 4685.2323314858. The cubic root of 21951402 is about 279.9974574599.

The spelling of 21951402 in words is "twenty-one million, nine hundred fifty-one thousand, four hundred two".