21225137810 has 8 divisors (see below), whose sum is σ = 38205248076. Its totient is φ = 8490055120.

The previous prime is 21225137809. The next prime is 21225137837. The reversal of 21225137810 is 1873152212.

It can be written as a sum of positive squares in 2 ways, for example, as 21068812801 + 156325009 = 145151^2 + 12503^2 .

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

It is a super-2 number, since 2×21225137810² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061256881 + ... + 1061256900.

Almost surely, 2^21225137810 is an apocalyptic number.

21225137810 is a deficient number, since it is larger than the sum of its proper divisors (16980110266).

21225137810 is a wasteful number, since it uses less digits than its factorization.

21225137810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122513788.

The product of its (nonzero) digits is 6720, while the sum is 32.

The spelling of 21225137810 in words is "twenty-one billion, two hundred twenty-five million, one hundred thirty-seven thousand, eight hundred ten".