651610421 has 16 divisors (see below), whose sum is σ = 838606848. Its totient is φ = 491367600.

The previous prime is 651610409. The next prime is 651610423. The reversal of 651610421 is 124016156.

It is a cyclic number.

It is not a de Polignac number, because 651610421 - 2¹⁰ = 651609397 is a prime.

It is a super-2 number, since 2×651610421² = 849192281511594482, 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 (651610423) 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, 134105 + ... + 138878.

It is an arithmetic number, because the mean of its divisors is an integer number (52412928).

Almost surely, 2^651610421 is an apocalyptic number.

It is an amenable number.

651610421 is a deficient number, since it is larger than the sum of its proper divisors (186996427).

651610421 is a wasteful number, since it uses less digits than its factorization.

651610421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273032.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 651610421 is about 25526.6609841554. The cubic root of 651610421 is about 866.9539049055.

Adding to 651610421 its reverse (124016156), we get a palindrome (775626577).

The spelling of 651610421 in words is "six hundred fifty-one million, six hundred ten thousand, four hundred twenty-one".